Tech Reference + How-To

Thanks for stopping by Southeast4x4trails.com! If you are looking for a detailed guide on how to install a GMRS radio or Ham radio in your Jeep or off-road vehicle you have come to the right place. Keep reading for more details about this 5-part series on my radio install project.

If you have found your way here via Google, this site is about the Jeep, 4×4, and off-road community in the Southeast US. Check out the home page for an interactive Google map of trails, off-road parks, forest service roads, points of interest and more in the GA, TN, NC, and SC areas. The Journal has other articles similar to this one on topics of interest such as “how-to” guides, trails and places to visit, and local history. The Resources page has many links to mapping, GIS, USFS forest areas, and technical info.

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This is the fifth in a series of 5 posts that detail the install of a Midland MXT400 MicroMobile GRMS radio and Icom IC-2730A ham radio in my Jeep Wrangler TJ. You can adapt this information to any vehicle, it doesn’t have to be a Jeep TJ or even a Jeep!

This post will cover the radio RF ground wires, running the radio power cables, running the antenna coaxial cables, attaching the PL-259 connectors to the antenna coaxial cables, and SWR meter testing.

Part 1 includes a complete list of all the radio gear, tools, parts, and hardware that I used.

If you want to jump directly to the install info just click one of the links below:

• Part 1 – Project Details, Gear, Parts and Tools
• Part 2 – Mounting the Midland MXT400 GMRS Radio and Icom IC-2730A Ham Radio
• Part 3 – Mounting the Radio Antennas
• Part 4 – Power, Wiring and Fuse Block Installation
• Part 5 – Radio Power Wiring and Antenna Coaxial Cable Installation

Before we get started I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items listed in the post through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

Parts List

The following parts were used in this post:
■ Midland MXT400 Power Cable (supplied with radio)
■ Icom IC-2730A Power Cable (supplied with radio)
■ RFI RFU-505-ST PL-259 UHF Crimp Style Coaxial Cable Connector (Qty: 2) – Antenna Farm or Ham Radio Outlet
■ Belden 14 Gauge Primary Wire in Red and Black (25-foot roll) – NAPA Auto Parts
■ Tyco Electronics 16-14 Gauge Heat-Shrink Spade & Ring Terminals for #8-#10 Stud – Home Depot
■ Dorman 16-14 Gauge Butt/Crimp Connectors (85436) – Advance Auto
■ Everbilt M4-0.7 X 8MM Phillips Flat Head Screw (574629) – Home Depot
■ Ideal Ground Screws (774042) – Home Depot
■ Storehouse 42 Piece Marine Heat Shrink Tubing – Harbor Freight Tools
■ XHF 160 Piece Clear Heat Shrink Tubing – Amazon
■ Gardner Bender 3.5 Foot Wire Spiral Wrap (FLX-538C10) – Home Depot
■ Littelfuse ATO 15 Amp Smart Glow Fuse (Qty: 2) (0AT0015.VPGLO ) – Amazon
■  Avery 06141 File Folder Labels – Amazon
■ Magnetic Mic Microphone Hanger – Amazon (Optional)

Tool List

The following tools were used in this post:
■ IWISS Ratchet Crimping Tool Set w/ 22-10 Gauge Wire Die – Amazon
■ LP DL-801G Ratchet Crimping Tool for RG58 Coaxial Cable – Ham Radio Outlet
■ Wagner Spraytech Heat Gun – Amazon
■ Wera PH0 Precision Screwdriver – Amazon
■ Dremel Rotary Tool – Amazon
■ Dremel 428 Carbon Steel Wire Brush – Amazon
■ Milwaukee 48-89-4607 Shockwave 5/32” Titanium Drill Bit – Amazon
■ Xacto Black Gripster Knife – Amazon
■ Surecom SW-102 S0239 Digital SWR Meter – Amazon
■ Superbat Male PL-259 to Male PL-259 RG-58 Coaxial Jumper Cable – Amazon (Optional)

Radio System Guide & Wiring Diagram

The graphic below shows the entire radio system and how each component is connected and wired. All parts that are in front of the ‘Jeep Firewall’ box are mounted in the engine compartment. Click to download the diagram in PDF format.

The components that are covered in this post are shown below in red.

1. Wire The Radio RF Grounds

Both radios should be grounded to a bare metal surface. The radio RF grounds make sure that both radios maintain the same RF voltage. This is also known as “bonding”.

To make the radio RF ground wires, cut two pieces of 14 gauge primary wire long enough to reach from the body of each radio up to the top of the overhead console. Strip away enough of the wire shielding to attach a 16-14 gauge ring terminal for a #8-#10 stud and slide a piece of 1/4″ marine heat shrink over the wire before you crimp (attach) the terminal to the wire.

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Slide the terminal over the wire and crimp it with a ratcheting crimp tool like the IWISS ratchet crimping toolset with a 22-10 gauge wire die or a fixed-style crimp tool such as the Klien Tools 1000.

Constrict the heat shrink with a heat gun. Attach a ring terminal and piece of marine heat shrink to the other end of the wire as well. Do the same with the second piece of primary wire.

On the Midland MXT400 GMRS radio, there is a pre-drilled hole on the rear of the radio body and in the center of the heat sink fins. This is a perfect place to attach the RF ground wire to the radio. Use an M4-0.7 X 8MM Phillips flat head screw to attach the terminal to the radio body.

On the Icom IC-2730A ham radio, there is a small screw on the side of the radio body near the rear. Use a PH0 precision screwdriver and slowly turn the screw to remove it. Do not do this quickly or you will risk stripping the screw head because it is so small.

Insert the screw through the ring terminal on the second piece of wire and re-attach it to the radio body.

2. Attach The RF Ground Wires To The Overhead Console

As mentioned above, the ring terminals should make contact with a bare metal surface. Use a Dremel rotary tool and a Dremel carbon steel brush attachment to remove a portion of the coating on the top of the overhead console.

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The coating on the overhead console is pretty thick (and durable), so take your time while removing the coating and let the brush do the work. You only need to remove enough of the coating so that the area is large enough to screw both of the ring terminals to the overhead console.

Test fit the terminals and use a marker to make a dot in the center of each ring terminal. Drill two pilot holes with a 5/32″ metal drill bit.

Clean the area to make sure it is free of any residue from the console coating and drill shavings. Secure the ring terminals against the overhead console with two Ideal ground screws. These ground screws are a #10-32 in size. Gather the wires together and secure them with a zip tie as well.

3. Route the Radio Power Cables

Both the Midland MXT400 and Icom IC-2730A come with DC power cables. Both of these cables are routed from the 6-circuit distribution fuse block under the passenger seat to the radios where they mounted on the overhead console.

Before you start routing the wires remove the plastic trim that is around the windshield. The power cables will be hidden by these trim pieces.

Attach each power cable to its connector on the radio body. Gently pull the plastic trim piece back that runs along the top of the windshield and insert each cable between the windshield frame and the trim piece – one cable at a time.

I zipped tied the power cables together once they were inserted between the trim piece and the windshield frame to keep them together. The plastic trim piece will not sit completely flush against the windshield once it is re-tightened, as the power cable wires will stick out of it at the top.

On the passenger side of the Jeep, route the power cables along the top of the windshield and then down the side of the windshield, behind the dashboard, and to the floor of the Jeep. I used zip ties to secure the cables to the existing factory wiring as shown in the photo below on the right below.

It is easy to forget which power cable attaches to which radio, so it is also a good idea to label both cables for easy identification. Use an  Avery 06141 file folder label on each wire and cover it with a piece of clear heat shrink. I placed the labels at a point on the cables that is near where the cables connect to the distribution fuse block.

4. Extend The Power Cable For the Midland MXT400

The power cable for the Icom IC-2730A was long enough to reach from the radio to the distribution fuse block. The power cable for the Midland MXT400 was not, however.

Extending the power cable is straightforward. Cut two lengths of 14 gauge primary wire that are long enough to run from where the MXT400 power cable stops to the distribution fuse block. Leave some extra slack in case you need to re-terminate the connectors on the cables in the future. Match red primary wire to the red wire on the MXT400 power cable, and black to black.

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Cut two pieces of marine heat shrink and crimp a 16-14 gauge ring terminal for a #8-#10 stud on each piece of wire (on the end of the extension wires – where it will connect with the distribution fuse block). Crimp the extension wires to the MXT400 power cable with two 16-14 gauge butt connectors and two pieces of marine heat shrink.

Cover the MXT400 power cable and the extension wires in plastic spiral wrap where they make contact with the floor of the Jeep as you did for the Icom IC-2730A power cable.

5. Attach The Power Cables To The Distribution Fuse Block

Remove the Phillips head screws for 2 positive terminals and 2 negative terminals on the distribution fuse block. If you are looking at the fuse block as shown in the photo below, the two positive terminals are those that have slots for the 15A fuses, and the negative terminals are those that do not have slots for the fuses.

I attached the power cable for the Icom IC-2730A to the terminals on the right side of the fuse block, and the power cable for the Midland MXT400 on the left side of the fuse block (as shown by the labels on each power cable).

Zip tie the power cable extension wires together for the MXT400. Insert two 15A fuses into the slots for each power cable. I also used the labels that are included with the Blue Sea Systems distribution fuse block and put them on the fuse block cover. ‘M’ is for the Midland MXT400 and “I” is for the Icom IC-2730A.

NOTE: Both of the radio power cables have 15A in-line fuses installed from the factory. Theoretically, you don’t need 2 sets of fuses (one in-line and one on the distribution fuse block). You could remove the inline fuse holders and use 16-14 gauge butt connectors to connect the power cable wires together, but I decided to leave them in place in case I ever removed the power cables and wanted to use them in another vehicle in the future.

Just keep in mind that if a fuse does blow, be sure to check both the in-line fuse and the fuse in the distribution fuse block. If you do choose to remove the in-line fuse holders, use a piece of marine heat shrink to cover each butt connector to protect it against water.

6. Route The Antenna Coaxial Cable

Routing the antenna coax cable is pretty much the same as routing the radio power cables. Route the coax cable behind the plastic windshield trim and secure it in place with zip ties.

The coax cable for the Midland MXT400 is routed on the passenger side (the antenna for the MXT400 is mounted on the passenger side fender), and the coax cable for the Icom IC-2730A is routed on the driver side of the windshield (the antenna is mounted on the driver side fender). Pass both coax cables out of the plastic windshield trim at the top just as you did with the power cables.

Determine how much length is needed for the coax cable to reach the antenna output connectors on the radio bodies. Keep in mind you will still need to attach the PL-259 connectors to the end of the coax cable. It’s best to leave extra slack and trim it down if needed. This also gives you enough coax cable to re-terminate (install new connectors) if needed in the future as well.

While some extra slack is not an issue, the coax cables should only be as long as they need to be to reach the antenna output connectors on radio bodies. Coiling up the excess coax cable and not cutting it to length is a bad idea and it will impact the overall radio/antenna performance and SWR measurements.

The antenna output connector is on the left side of the Icom IC-2730A radio body and the right side of the Midland MXT400 radio body (if you are looking at the radio body from the rear).

Label both of the coax cables as well so it is easy to identify which cable goes to which antenna.

7. Attach The PL-259 Connectors

This was one of the most difficult steps of the install for me. Mainly that is because I had never installed connectors onto a piece of coax cable before. If it is your first time installing connectors as well, these are a couple of tips that I would suggest:

• Order EXTRA PL-259 connectors and use them to practice the installation first
• Use a piece of the excess coax cable that you cut when trimming in step 6 (or buy a few feet of extra cable) to practice
  • I ended up making a short jumper coax cable with my practice installations – you can use this jumper cable in step 8 for the SWR meter testing. I used a length of coax cable that was about 12″ and installed two of the extra PL-259 connectors onto each end
• You can buy a special tool for stripping RG-58 coax cable. I bought one and it ended up cutting too deep and through most of the braided shielding on the coax cable. The depth of the cut is usually adjustable, but I didn’t want to go through the process of adjusting/cutting so I just used a sharp Xacto knife and made multiple, shallow cuts on the coax cable until it was properly stripped.
• Use the crimp style PL-259 connectors. There is debate over the quality of the connection on a solder vs. crimp style connector, but the crimp style connector is far easier to install and is perfectly suitable for this application (and is used in many professional radio gear installations as well).
• Use a ratcheting crimping tool to install the PL-259 connectors

You will need two PL-259 connectors and the ratcheting crimping tool mentioned above. I used the RFI RFU-505-ST connectors and the LP DL-801G ratchet crimping tool for RG-58 coax cable/connectors.

Before you strip the coax cable, slide the PL-259 connector ferrule and connector body over the coax. Also cut a piece of marine heat shrink and slide it down the coax cable as well. The order for each piece is marine heat shrink (covers the ferrule once crimped) > ferrule > connector body. Do this for both coax cables.

Next, manually strip enough of the coax cable to install the connector. Be CAREFUL when stripping – if you make several errors while stripping and have to cut the coax cable and start there is a chance of it becoming too short to reach the antenna connector output on the radio body. If this happens you will have to remove, replace and re-run the coax cable all the way from the antenna mounting brackets that are on the fender of the Jeep – this is A LOT of work to undo and redo.

You can use the top of the overhead console as a solid workspace while stripping the coax cables as well.

I watched many videos on YouTube on how to install the PL-259 connectors. You can find them by searching the term ‘how to crimp PL-259 connectors‘. The type of coax used in this project is RG-58.

The die size to use on the ratchet crimping tool is .213 for the connector ferrule and .069 for the center conductor wire.

This is one of the better videos that I watched and used it primarily to learn how to do the installation. It’s much easier to watch someone do it than to try and learn from just photos. Remember, PRACTICE FIRST before you install the connectors on the “real” coax cables for the radio antennas!

Once the connectors are installed, screw them onto the antenna connector outputs on the radio bodies and make sure they are snug.

Reinstall the plastic windshield shield trim pieces and your install is COMPLETE!!!

8. SWR Meter Testing

A SWR meter, or “standing wave ratio” (also known as a VSWR meter – voltage standing wave ratio) is used to test the SWR ratio of a transmission line (the antenna coax cable). This is the ratio of how much of the output power from the radio is being delivered to the antenna and how much power is reflected by the antenna and back to the radio.

Measuring SWR is important for two reasons. First, if too much power is being reflected by the antenna back to the radio it can cause significant damage to the radio depending on how high the SWR ratio is. Second, it is a tool that can be used to tune the antenna for optimal signal transmission and performance.

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An SWR reading of 2.0 or numerically lower is generally considered safe to operate without the worry of radio damage. Any SWR reading numerically higher than 2.0 is considered increasingly unsafe and you risk the potential of damage. An SWR reading of 3.0 or higher means you will damage the radio if you are transmitting for an extended amount of time.

The “ideal” SWR reading is in the 1.0 to 1.5 range.

I used the Surecom SW-102 S0239 Digital SWR Meter and an RG-58 coaxial cable jumper of about 12″ that I made with the excess coax cable and male PL-259 connectors while practicing the connector installation (as mentioned above in step 7). You can also purchase pre-made coax jumper cables as well.

The SWR meter has to female PL-259 connectors on each side. Attach the coax jumper cable to the antenna output on either radio and the other end of the jumper cable to the input on the left side of the meter labeled TX. Attach the coax cable that runs to the antenna to the connector on the right side of the meter labeled ANT.

Make sure you are in an open area such as an empty parking lot and at least 20 feet away from any buildings, structures, vehicles, or metal objects. If they are closer than 20 feet it can affect the signal being transmitted to the antenna and in turn, the SWR meter reading could be inaccurate.

On the Surcom SW-102 SWR Meter, press and hold the red button to power the meter on. Once it is on, by default it is set up to take the SWR reading when you key the radio microphone to transmit.

Typical advice when testing SWR for an amateur radio (or GMRS for the Midland MXT400) is to start at the bottom of the band and take a reading, tune to the middle of the band and take a reading, then tune to the top of the band and take the third reading. This allows you to measure the average SWR reading across the entire band.

So, on the Icom IC-2730A ham radio on the 2-meter band that would be 144 Mhz on the low end of the band, about 146 Mhz in the middle of the band, and 148 MHz on the upper end of the band. For the 70-cm band that would be 420 Mhz, 440 Mhz, and 450 Mhz, respectively.

On the Midland MXT400 GMRS radio, you could take readings at the 462 MHz portion of the band (channels 1-7), 467 Mhz portion of the band (channels 8-14), and then again at 462 MHz but at higher GMRS power (channels 15-22). See this frequency chart for the specific frequencies for each channel and allowed output power.

These frequencies are approximations and don’t have to be exact, so make sure the frequency is clear before you transmit.

When you key the microphone to transmit, the SWR reading will display on the meter. It also measures the actual output power as well.

These are photos of the actual SWR readings I took after I finished the install. On the left, you can see that the SWR reading was 1.95 on 146.010 MHz at an output power of 46.4W (not quite the 50-watt max output power) for the Icom IC-2730A.

On the right, the SWR for the Midland MXT400 was 2.01 on 462.550 MHz at 32.3 watts (also not quite the max output power of 40 watts).

Depending on the SWR readings that you get, you can determine if additional antenna or system tuning is needed. I did not take any further steps to tune the antennas based on these two readings, but I may do so in the future.

If you are interested in learning more about how to tune the antennas, read post #50 in the original RadioReference.com forum post about this installation projects.

These articles and video also provide some additional information about SWR testing, interpreting the readings and antenna tuning:

• How to Use A SWR Meter To Test Antenna Standing Wave Ratio (SWR)
• What is SWR And Why Is It So Important?
• Rugged Radios Tech Tip: How To Use An SWR Meter (Video)

9. Magnetic Mic Microphone Hanger

This is completely optional, but I did find it to be very helpful while on the trail. The Magnetic Mic microphone hanger replaces the hanger that is supplied with the radio. It isn’t compatible with the Icom IC-2730A mic, but it does work with the Midland MXT400 mic. Most of the people I ride with use GRMS radios on the trail, so the mic for the MXT400 is the one that I take on and off its hanger all day.

The Magnetic Mic hanger is exactly what it sounds like. It has a strong magnetic base and another magnet that attaches the circular piece on the back of the MXT400 mic. Since the magnet is very strong, all you have to do is get the mic in the general area of the hanger base and it will snap to it. Very handy while bouncing up and down on the trails.

Wrapping Up

Congratulations on completing this installation project. It is far more work than your average ham or GMRS radio install. You can rest easy knowing that your radio system is made up of top quality gear and is installed the right way. I think you will be pleased with the radio system’s performance.

Feel free to reach out to me with any questions that you might have and I will do my best to help. You can reach me via e-mail from the About page or on Facebook at Southeast4x4Trails.com.

Thanks for stopping by Southeast4x4trails.com! If you are looking for a detailed guide on how to install a GMRS radio or Ham radio in your Jeep or off-road vehicle you have come to the right place. Keep reading for more details about this 5-part series on my radio install project.

If you have found your way here via Google, this site is about the Jeep, 4×4, and off-road community in the Southeast US. Check out the home page for an interactive Google map of trails, off-road parks, forest service roads, points of interest and more in the GA, TN, NC, and SC areas. The Journal has other articles similar to this one on topics of interest such as “how-to” guides, trails and places to visit, and local history. The Resources page has many links to mapping, GIS, USFS forest areas, and technical info.

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This is the fourth in a series of 5 posts that detail the install of a Midland MXT400 MicroMobile GRMS radio and Icom IC-2730A ham radio in my Jeep Wrangler TJ. You can adapt this information to any vehicle, it doesn’t have to be a Jeep TJ or even a Jeep!

This post will cover the radio electrical distribution system and the installation of the maxi fuse block, 6-circuit power distribution block, Lind shutdown timer, Insultherm braided shielding and the manual override switch.

Part 1 includes a complete list of all the radio gear, tools, parts, and hardware that I used.

If you want to jump directly to the install info just click one of the links below:

• Part 1 – Project Details, Gear, Parts and Tools
• Part 2 – Mounting the Midland MXT400 GMRS Radio and Icom IC-2730A Ham Radio
• Part 3 – Mounting the Radio Antennas
• Part 4 – Power, Wiring and Fuse Block Installation
• Part 5 – Radio Power Wiring and Antenna Coaxial Cable Installation

Before we get started I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items listed in the post through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

Parts List

The following parts were used in this post:
■ Lind SDT1230-022 Shutdown Timer – Amazon | Lind
■ I bought 2 of these in new condition on Amazon for $22.99. The retail price from Lind is $81.95.
■ Blue Sea Systems Maxi Fuse Block / In-Line Fuse Holder (5006) – Amazon 
■ Blue Sea Systems ST Blade ATO/ATC Fuse Block (6 Circuit w/ Negative Stud Terminals ) (5025) – Amazon
■ Blue Sea Systems Contura II Off-(ON) SPST Switch – Amazon 
■ Daystar Universal Firewall Boot (KU20040BK) – Amazon | Quadratech
■ Insultherm High Temp Braided Sleeving – 1.5″ and 5/8″ – Wire Care
■ WindyNation 8 AWG Gauge Pure Copper Flexible Cable Wire – 30 Feet, Red (Battery Positive) – Amazon 
■ Windy Nation 8 AWG Gauge Pure Copper Flexible Cable Wire – 15 Feet, Black (Battery Negative) – Amazon
■ Belden 14 Gauge Primary Wire in Red, Black (25 Feet) – NAPA Auto Parts
■ Selterm Heavy Duty Bare Copper Terminals for 8 AWG Gauge Wire, #10 Ring Stud– Amazon (Qty: 6)
■ Selterm Heavy Duty Bare Copper Terminals for 8 AWG Gauge Wire, 1/4” Ring Stud – Amazon (Qty: 1)
■ NAPA Auto Parts In-Line Mini Fuse Holder (784667) – NAPA Auto Parts
■ Blue Sea Systems 30 Amp Maxi Fuse (5138) – Amazon
■ Littelfuse ATO 15 Amp Smart Glow Fuse (Qty: 2) (0AT0015.VPGLO ) – Amazon
■ Littelfuse 5 Amp Mini Fuse (0MIN005.VP) – Amazon ($3.81)
■ Dorman 16-14 Gauge Butt/Crimp Connectors (85436) – Advance Auto
■ Dorman 16-14 Gauge 1/4″ Ring Terminal (85409) – Advance Auto (Qty: 1)
■ NAPA Auto Parts 16 to 14 Gauge Step Down Butt/Crimp Connector – NAPA Auto Parts
■ Tyco Electronics Raychem #10 Spade & Ring Terminals for 16-14 Gauge Wire – Home Depot (Qty: 1)
■ MaxBrite 16-14 Gauge Fully Insulated Female Disconnect Terminals – Amazon (Qty: 2)
■ Ideal Ground Screws (774042) – Home Depot
■ Storehouse 42 Piece Marine Heat Shrink Tubing (Qty: 2) – Harbor Freight Tools 
■ XHF 160 Piece Clear Heat Shrink Tubing – Amazon
■ Gardner Bender 3/8” & 1/2” Electrical Split Flex Tubing (FLX-538C10) – Home Depot
■ Gardner Bender 3.5 Foot Wire Spiral Wrap (FLX-538C10) – Home Depot
■ Gorilla Glue Heavy Duty Mounting Tape – Amazon
■ Rust-Oleum Clean Metal Flat White Primer (7780830) – Amazon
■ Rust-Oleum Flat Black Protective Enamel (7776830) – Amazon
■ Rust-Oleum Universal Dead Flat Clear Durable Topcoat (342482) – Amazon

Radio System Guide & Wiring Diagram

The graphic below shows the entire radio system and how each component is connected and wired. All parts that are in front of the ‘Jeep Firewall’ box are mounted in the engine compartment. Click to download the diagram in PDF format.

The components that are covered in this post are shown below in red.

1. Install The Maxi Fuse Block

Before your start step 1 make sure you DISCONNECT the battery terminals from the battery.

The maxi fuse block protects the radio power system against high or excess current flow if something fails. Maxi fuses are larger than your “regular size” ATO/ATC fuses, and are typically designed specifically for higher amperage vehicle electric systems.

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The Blue Sea Systems 5006 Maxi Fuse Block encloses both the fuse and the connector terminals within the plastic housing. This is important because the maxi-fuse block is mounted in the Jeep engine compartment and will be exposed to the elements. This fuse block accepts maxi fuses from 30-80 amps, but a Blue Sea Systems 5138 30 amp maxi-fuse is sufficient for the radio power system.

terminals and if you tighten the screws the maxi fuse will not fully seat in position due to the tension applied by the terminal screws.

Leaving some slack also allows you to route the wire from the battery to the fuse block a bit easier as well. The terminal screws on the fuse block are #10 size. To crimp (attach) the copper terminal to the wire, strip back about 1/2″ of the exterior shielding on the wire and twist the wire strands to make sure they are wrapped together tightly. No wire strands should extend outside of the terminal when it is crimped.

On one end of the wire cut a ~1.5″ piece of 3/8″ marine heat shrink and slide it over the end of the wire. Next, attach a Selterm #10 ring stud 8 gauge heavy-duty copper terminal using a ratcheting crimping tool such as the Fryic ratchet crimping tool for 20-7 gauge wire. I found it easier to place the copper terminal in the crimping tool first, then insert the wire and crimp. The ratcheting crimping tool will make sure your crimp connection is tight around the wire. The ratchet motion allows you to create more force as compared to a fixed crimping tool creates.

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However, before you crimp the connector test fit the stripped length of the wire into the terminal to make sure excess wire is not exposed outside of the end of the terminal. Ideally, just strip away enough of the shielding to fit the exposed wire into the terminal so that the wire shielding sits up against the end of the terminal. When crimping the terminal make sure you crimp the entire length. Complete one crimp, then slide the crimping tool over and complete another crimp. See the photos below for reference.

For the terminal on the other end of the wire, check the size of the post on your battery positive terminal. The post on my battery is 1/4″, so I used a Selterm 1/4″ ring stud 8 gauge heavy-duty copper terminal along with another piece of 3/8″ marine heat shrink.

Once both terminals are attached to the wire, use a heat gun to contract the heat shrink material over the copper terminal and the wire. Heat the heat shrink material until you can see a bit of the glue expand outside of the ends of the heat shrink material. The marine heat shrink material uses this “glue” type material to create a seal that is resistant to water (marine).

Do not attach the wire to the battery post and fuse block quite yet. There are a couple of additional steps to complete first.

IMPORTANT – Label the red battery positive wire. It is easy to get the wires mixed up and forget which wire is which once you start routing them through the Jeep firewall and into the cabin.

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For the labels, I used regular Avery 06141 file folder labels that you can buy on Amazon or at any office store. These labels have marks on each side at the center of the label. I aligned those marks with the center of the wire (as best I could). Attach the label to the wire, then slide a piece of clear heat shrink over the label and heat it up for a nice, weatherproof seal. I put ’12V+ to Maxi Fuse Block’ on the label.

After the label is attached to the wire, cover the entire length of the wire with both plastic spiral wrap and plastic split flex tube. This helps protect the wire from melting or damaged from heat since it is in the engine compartment of the Jeep. Use a plastic zip tie on each end of the wire to secure the spiral wrap and split flex tube in place. Make sure you pull the zip tie tight so the plastic tubing can not slide up and down on the wire. A zip tie puller tool helps to make sure the tie is tight and secure.

Next, repeat the same process to attach terminals to the wire that will run from the maxi fuse block, through the Jeep’s firewall and into the cabin and the Lind shutdown timer. This will provide the power to the shutdown timer, and in turn to the larger in-cabin 6-circuit fuse block.

Attach another Selterm #10 ring stud 8 gauge heavy-duty copper terminal to one end of the 8 gauge red wire along with another piece of 3/8″ marine heat shrink. Cover it with spiral wrap and split flex tube from where it attaches to the maxi fuse block terminal to where it will pass through the Jeep firewall.

Do not cut the length of the wire that will run through the firewall and into the cabin yet. That wire will be routed into the cabin first, then it can be cut to the appropriate length based on where it will connect to the terminal on the Lind shutdown timer. Once the wire is cut to that length, attach another Selterm #10 ring stud 8 gauge heavy-duty copper terminal.

Next, attach both pieces of wire to the terminals on the maxi fuse block. Turn the terminal connectors so the curve of the connector is facing the maxi fuse block – basically connecting them “backwards” so that the curvature of the connector faces inward. The cap to the maxi fuse block will not fit if you attach the connectors the other way. See the photo below for reference.

Before you tighten the terminals screws insert the maxi fuse into the fuse block. Then tighten the terminal screws and place the cover onto the fuse block.

I routed both wires so they run from the fuse block and through the space in between the air filter box and the Jeep fuse panel. I zip-tied both of the wires together then just tucked them down into the space between the air filter box and fuse panel.

Set the wires aside near the battery for now. There are a couple of other steps before you route them through the Insultherm bradied shielding and into the cabin of the Jeep.

2. Run Wire For 12V Constant Power To The Manual Override Switch

The reason for the manual override switch is explained below, but the next step is to wire up a source of 12V constant power that will connect to PIN 2 on the Blue Sea SPST (single-pole, single-throw) momentary switch. This power will be supplied directly from the battery positive terminal to PIN 2 on the switch.

I tried to find a fuse/circuit on the OEM interior Jeep fuse block that supplied constant 12V power, but all of the available or open fuses were ignition switched. This means that no power is present when the Jeep ignition is in the OFF position. For the switch to operate as needed, it requires a source of 12V constant power regardless of if the Jeep ignition is switched ON or OFF.

For now, you just need to attach a ring terminal to a length of 14 gauge wire such as Belden 14 gauge primary wire. I had some 14 gauge wire in green available, but you might consider using red (wire) to indicate that it is a “hot” power wire. If you are using a new roll wire (usually 25 feet) just attach the terminal to one end of the wire, then it can be cut to the appropriate length once the wire is routed through the firewall and into the Jeep cabin and switch.

Select the appropriate size ring terminal for your battery post. I used a Dorman 16-14 gauge wire 1/4″ ring terminal. Cut a piece of 1/4″ diameter marine heat shrink and slide it over the 14 gauge wire, then measure and strip the wire shielding.

3. Install The Firewall Boot

I used a Daystar Universal Firewall Boot with a small modification to pass the wiring through the Jeep firewall. The firewall boot offers several advantages as compared to either just cutting a hole in the existing OEM firewall plug or removing it completely and passing the wiring through the factory firewall hole.

I did cut off one additional section of the firewall boot to make enough room for all of the wiring to pass through the end of the boot that is in the Jeep engine compartment.

4. Route Wiring Through Insultherm Braided Sleeving

The path from the Jeep’s battery down to where the wiring will pass through the Jeep firewall runs very close to the exhaust manifold on the engine. This means that the wiring will be subject to high temperatures, and the last thing you want to do is have to re-run all the wiring again if it melts or fails due to high heat.

To protect the wiring against the heat, I used 2 sleeves of Insultherm high-temp braided sleeving. This sleeving is rated to protect up to temperatures of 1,200 degrees which is plenty sufficient for this application. I ordered a 3-foot piece of 1.5″ diameter sleeving and a 3-foot piece of 5/8″ diameter sleeving.

The following wiring will pass through the 1.5″ diameter Insultherm sleeving:

• 8 gauge red power wire for the Lind shutdown timer (from the maxi fuse block)
• 14 gauge 12V+ constant power wire for the manual override switch (from the Jeep battery)
• Antenna coax for the Larsen NMO450CHW antenna (see part 3)
  • Cover the coax wire with spiral wrap and split flex tubing

The following wire will pass through the 5/8″ diameter Insultherm sleeving:

• Antenna coax for the Larsen NMO 2/70B (see part 3)
  • Cover the coax wire with spiral wrap and split flex tubing

Start with the larger 1.5″ diameter sleeving. Pass the 3 wires listed above through the sleeving and towards the hole in the Jeep firewall.

Next, route the antenna coax for the Larsen NMO 2/70B antenna through the 5/8″ piece of Insultherm sleeving.

To pass the antenna coax through the Insultherm sleeving I detached the NMO mount from the mounting brackets on the front fenders. I used an electrician’s wire fish tape tool and attached the curved end of the fish tool around the NMO mount as shown below. I then pulled the antenna coax through the sleeving and re-attached the NMO mount to the mounting bracket. This will leave the bare (no connector yet) end of the antenna coax wire ready to pass through the firewall boot.

5. Pass Wiring Through Firewall Boot

Unfortunately, there is not really an “easy” way to pass all of the wiring through the firewall boot. First, I figured out where I could cut the split flex tubing on each wire so that the tubing stopped at the point where the wire entered the firewall boot. This leaves just the wire and spiral wrap to pass through the boot and into the Jeep cabin.

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Next, I worked one wire at a time through the firewall boot. Hold the boot with one hand and work each wire through until you can grab it with something (either your hand or a pair of needle-nose pliers) and pull it through the boot and into the cabin. You will have to work each wire through slowly until you are able to grab it. I tried to use the wire fish tape tool to pull the wiring through the boot put given the available space in the boot it didn’t really work well at all.

Pass all 4 wires through the firewall boot and pull the slack through into the cabin. We will come back in a later step and secure the Insultherm sleeving in the engine bay. You may need some extra slack or to cut a wire to a shorter length once it is attached to its endpoint/component.

6. Mount The Lind Shutdown Timer

The Lind shutdown timer solves a couple of issues that I encountered when I first installed the radio system. Initially, I installed a 4-pin relay and a DPDT (double-pole, double-throw) switch that had to be in an ON position to supply power to the radio system.

About a week after I finished the install I went to start the Jeep one day and the battery was dead. The DPDT switch had a light that was always on, so I suspect it slowly drained the battery. I charged the battery up once and it slowly discharged again, so I removed the relay and DPDT switch.

The Lind shutdown timer is designed to turn off after a preset amount of time once the Jeep engine is shut down. This kills all power to the radio system once the preset amount of time is reached. I set the timer to turn off 30 minutes after the Jeep engine is turned off. The timer also has a built-in relay to handle power switching.

You can use the SPST (single pole, single throw) manual override switch in the Jeep cabin to tell the timer to turn on again even when the Jeep engine is shut down. This allows you to operate the radio system if you need to when the Jeep isn’t running.

As outlined in the wiring diagram at the top of the page, the 12V power to the timer comes from the maxi fuse block and connects to the +BAT terminal on the timer. One of the +OUT terminals on the timer supplies the 12V power to the larger Blue Sea 6-circuit fuse block. The GND terminal on the timer is grounded to the Jeep battery, and PIN 3 (LOAD) on the SPST manual override switch runs to the IGN terminal on the timer.

I mounted the shutdown timer on the passenger side firewall underneath the carpet on the floorboard. Use two pieces of Gorilla Glue heavy-duty mounting tape (it’s rated to hold up to 30 pounds) as shown above. Stick the timer to the firewall and firmly hold it in place for 1-2 minutes so the mounting tape bonds to the firewall. This much easier than trying to attach the timer to the firewall with screws. The +OUT and +BAT terminals on the timer should be facing the passenger side of the Jeep.

It is much easier to mount the timer if you remove the passenger seat. Use a T50 Torx bit to remove the bolts on the passenger seat frame.

7. Attach the 8 Gauge 12V Power Wire To The Shutdown Timer

Now that you have routed all of the wires through the Jeep firewall pass the red 8 gauge power wire behind the dash and over to the passenger slide floorboard where the timer is mounted. Determine where you can cut the wire and attach it to the +BAT terminal on the timer.

8. Wire the Shutdown Timer Ground

To ground the shutdown timer, use a piece of 14 gauge primary wire, preferably in black to represent that it is a ground wire. Cut and slide a piece of 1/4″ marine heat shrink onto the wire, then attach a #10 ring terminal for 16-14 gauge wire to one of the wire with either a rachet or fixed crimping tool. Apply heat to the heat shrink until it contracts the glue runs out of the end of the tubing.

To create a proper ground connection remove a bit of the paint from the area where you will attach the wire to the Jeep body. I attached the wire just above the shutdown timer (see photo below). A Dremel 428 carbon steel wire brush makes removing the paint nice and easy. You only need to remove just enough so the ring terminal makes contact with the bare metal on the firewall.

To attach the wire to the firewall drill a small pilot hole first, then secure it with a #12-3/4″ self drilling screw. On the opposite end of the ground wire, strip a small portion of the shielding back and attach the wire to the GRD terminal on the timer by loosening the screw in the terminal, insert the wire into the terminal opening, and re-tighten the screw.

All of the wires are attached to the timer in the photo below. This includes both the 8 gauge power wire that will run to the 6-circuit fuse block and the wire from the SPST manual override switch.

9. Wire The Manual Override Switch

Connect the 16 gauge end (this end is marked by the black band on the connect, see in the photo above) to the inline fuse holder. On the other end of the inline fuse holder, crimp the 16 gauge end of another step-down butt connector to the fuse holder. Cut another length of 14 gauge wire that will run to the switch (red in the photo above), and connect it to the 14 gauge end of the butt connector. You can use marine heat shrink on these connections as well.

Insert a Littlefuse Mini 2 Amp Fuse into the fuse holder and place the fuse holder in a secure place within the glove box.

The switch will fit in the factory Jeep TJ switch pod. Remove the center dash bezel and the switch pod and place the switch into one of the open holes. When the switch is seated in the holder it will look like the photo below.

Cut a length of 14 gauge primary wire to run from PIN 3 on the switch to the IGN terminal on the shutdown timer. Attach 2 16-14 gauge female disconnect crimp terminals to the 12V constant wire and the IGN wire along with marine heat shrink on each wire. Seat the female disconnect terminals onto their respective switch pins and re-attach the switch pod and the center dash bezel. Label both of the wires as well.

10. Mount The 6-Circuit Fuse Block

The radio power leads connect to the Blue Sea Systems 5025 ST Blade ATO/ATC fuse block. Using this type of fuse block allows you to run one source of power from the battery to the fuse block, and power multiple devices from the fuse block instead of running individual power leads for each device (to the Jeep battery). The fuse block I used allows you to attach up to 6 circuits/devices.

Mount the fuse block under the passenger seat (leave it out of the Jeep until the install is finished). You will need to remove the factory jack that comes with the Jeep and cut off the 2 mounting tabs for the jack so the fuse block will fit in this space.

Use a pair of pliers to bend the tabs over into a position where they can be cut off. I used a Ryobi 9340 rotary tool and a Dremel MM485 carbide flush cut oscillating (rotary) blade to make the cuts.

Next, cut a piece of 3/4″ plywood to a dimension of 7.5″ (long) x 4.5″ (wide). The fuse block will be mounted to the plywood, and the plywood is attached to the Jeep body. Test fit the piece of plywood in the mounting location once the cuts are made.

Mark the locations of the mounting holes with a marker or something pointed such as a drill bit. Attach the fuse block to the plywood with 4 5/8″ screws and place the fuse block in the mounting location. Do not screw it to the Jeep body yet in case you need to make any adjustments while running the radio power lead (covered in part 5 of this post series).

11. Run 8 Gauge Power Wire & Ground Wire to Fuse Block

Attach a Selterm 8 gauge #10 heavy-duty copper terminal to a piece of red 8 gauge wire with a piece of marine heat shrink. Label the wire ’12V Power From Timer +OUT’ and place a piece of clear heat shrink over the label. Attach the wire to the +OUT terminal on the Lind shutdown timer and the + (positive) terminal on the right side of the fuse block. Cover the wire in spiral wrap as well since it will sit on the floor of the Jeep body.

Next, cut a length of about 7″ of 8 gauge black wire and attach a Selterm 8 gauge #10 heavy-duty copper terminal to both ends of the wire. Attach one end of the wire to the – (negative) terminal on the left of the fuse block. Remove some of the paint on the Jeep body with a Dremel 428 Carbon Steel Wire Brush and drill a hole for the Ideal #10-32 self-tapping ground screw. Attach the other end of the wire to the Jeep body with the ground screw.

12. Secure The Insultherm Sleeving

You are almost done! Now that all of the components and wiring are installed for the power system, secure the Insultherm sleeving in place with zip ties in the Jeep engine compartment.

On the 1.5″ diameter Insultherm sleeving fold any excess slack in the sleeving over (“roll it up”) and place zip ties around it to keep the sleeving and wires tight. Do this along the entire length of the sleeving. Do the same thing for the 5/8″ sleeving as well.

Secure both pieces of Insultherm sleeving to the the existing Jeep wiring split flex tube as shown in the photos below.

Up Next – Part 5

Part 5 in this series the last step of the install! It will cover the radio RF grounds, running the radio power leads to the 6-circuit fuse block, installing the PL-259 connectors on the antenna coax wires, and how to do an SWR meter test. Check it out next!

Thanks for stopping by Southeast4x4trails.com! If you are looking for a detailed guide on how to install a GMRS radio or Ham radio in your Jeep or off-road vehicle you have come to the right place. Keep reading for more details about this 5-part series on my radio install project.

If you have found your way here via Google, this site is about the Jeep, 4×4, and off-road community in the Southeast US. Check out the home page for an interactive Google map of trails, off-road parks, forest service roads, points of interest and more in the GA, TN, NC, and SC areas. The Journal has other articles similar to this one on topics of interest such as “how-to” guides, trails and places to visit, and local history. The Resources page has many links to mapping, GIS, USFS forest areas, and technical info.

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This is the third in a series of 5 posts that detail the install of a Midland MXT400 MicroMobile GRMS radio and Icom IC-2730A ham radio in my Jeep Wrangler TJ. You can adapt this information to any vehicle, it doesn’t have to be a Jeep TJ or even a Jeep!

This post will cover the installation of the radio antenna mounting brackets, attaching the antennas for both radios to the mounting brackets, and the initial routing of the antenna coaxial cables.

Part 1 includes a complete list of all the radio gear, tools, parts, and hardware that I used and Part 2 includes a radio system guide and wiring diagram.

If you want to jump directly to the install info just click one of the links below:

• Part 1 – Project Details, Gear, Parts and Tools
• Part 2 – Mounting the Midland MXT400 GMRS Radio and Icom IC-2730A Ham Radio
• Part 3 – Mounting the Radio Antennas
• Part 4 – Power, Wiring and Fuse Block Installation
• Part 5 – Radio Power Wiring and Antenna Coaxial Cable Installation

Before we get started I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items listed in the post through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

Parts List

The following parts were used in this post:
■ Larsen NMOKHFUD NMO 3/4” Mobile Antenna Mounts + Coaxial Cable w/ No Connector (Qty: 2)
■ Larsen NMO 2/70B Antenna (For Icom IC-2730A)
■ Larsen NMO450CHW Antenna (For Midland MXT400)
■ Laird SBT3400 NMO Straight Antenna Mounting Brackets (Qty: 4)
■ NOTE: This straight-style bracket will NOT work with a Jeep JK or JL. You will need a JK or JL-specific bracket with a 3/4″ NMO hole such as this one from Antenna Farm or Topsy Products.

RadioReference.com Forum

Please note that some of the information in this post is adapted from a forum thread that I posted on RadioReference.com named “Multiple Antenna Question for 2M/70CM” I was fortunate enough to have several very, very knowledgeable and helpful people respond to my post and help me figure out the installation plan for this project. I have including some of the details from that forum thread in this post for your benefit. Some of the knowledge behind the various components of the radio system are key to understanding why those components were selected and what makes their performance superior to your average radio gear install.

Antenna Ground Plane – Why Is It Important?

Don’t skip over this section – it is important and relates to how well your radio will perform.

When it comes to installing antennas for mobile radios on vehicles, the generally accepted “ideal” scenario is one where you are able to mount the antenna on top of a metal roof on the vehicle. The antenna is mounted on the roof by either drilling a hole through the roof and installing the antenna mount (such as an NMO) or by using a magnetic mounting base.

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Either of those mounting methods allows the metal surface of the roof to connect to the antenna, where the metal roof of the vehicle services as what is called a “ground plane”. A ground plane is a “flat or nearly flat horizontal reflecting surface that serves as part of the antenna and reflects the radio waves from the other antenna elements.” (Wikipedia)

So, if you are mounting the antennas on a Jeep you do not have a metal roof – it’s either a fabric material if you run a soft-top or fiberglass if you run a hardtop.

Yes, there are other flat metal surfaces to mount the antenna on, but the size and area of the flat metal surface is important if that surface is going to act as a ground plane for the radio antenna(s). If you are using a GMRS radio, 2-meter or 70cm Ham radio, there isn’t a flat metal surface large enough on the Jeep to serve as a ground plane.

What is important is that you use what is called a “no ground plane” antenna for the frequency that your radio will transmit on. Both of the antennas that I installed are “no ground plane” antennas – the Larsen NMO450CHW for the Midland MXT400 GMRS radio and the Larsen NMO2/70B for the 2-meter/70cm Icom IC-2730A Ham radio.

In technical terms, both the NMO2/70B and NMO450CHW are 1/2 wave antennas which means that the length of the antenna whip (long metal piece) is equal to 1/2 the length of the full RF wave for the bands they are designed to operate on. This length allows the antennas to work without a ground plane.

The information available on “no ground plane” and “ground plane” antenna setups is virtually endless. If you would like to learn more about these concepts, Google either of those terms but beware it gets very technical very quickly. My goal in this post is to highlight why a “no ground plane” antenna is the correct choice for these radios when they are mounted on a Jeep.

Antenna Mounting Location on the Jeep

I mounted the antennas for the MXT400 and IC-2730A on the front fenders of my Jeep. If you are wondering why I mounted them on the front fenders and not in the rear of the Jeep as many people do, the short answer is mounting any radio antenna on the rear of a Jeep Wrangler is not a good choice if you want to maximize the signal range, quality of your radio communications and the radio’s overall performance.

In part 1 of this series I went into more detail about why mounting the radio antennas on the front fender was a better location, but this is the main takeaway:

Why? Because typically there are multiple obstructions in the rear of Jeep (tire carrier, hard/soft top, other radio antennas, etc.) that affect the path and emissions of the RF waves that your radio antenna transmits. It alters the radio wave propagation pattern which means it impacts (makes it worse) the radio’s performance.

If you would like to read more about this topic, visit the ‘Project Background and Detail’ section in Part 1. In fact, when I first installed the MXT400 I mounted the antenna on the rear tire carrier before I had any clue about the disadvantage mounting it in that location.

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1. Reinforce the Antenna Mounting Brackets

Both of the antennas are mounted on Laird SBT3400 NMO straight brackets. You will need 4 total brackets, 2 for each fender. Joining two brackets together provides a stronger base that is less likely to bend the brackets.

Another lesson learned from the first time I installed the antennas – if the antenna coil gets hung up in trees or branches, it will bend the mounting bracket.

After I initially finished this project, I went on a trip the following weekend to an area that had pretty thick tree cover throughout the entire trail. The leaves on tree branches kept getting caught in the open coil on the Ham radio antenna (Larsen NMO2/70B) and it almost ripped the mounting bracket off the fender. Also, another handy trick is to put a piece of heat shrink around the antenna coil so leaves and branches will not get caught in it to start with (see the end of this post for a photo).

First, use a strong adhesive such as Gorilla Glue Clear Epoxy (part 4200101) to bond two of the mounting brackets together. Follow the directions on the package to mix the epoxy together. You can use the package as a mixing tray as well.

Coat the inside of both brackets with the epoxy and align them by sliding them into position with your fingers. They will slide pretty easily, so make sure all 4 sides on both brackets are aligned and square. While holding both brackets together with one hand, attach a clamp and slowly tighten it to make sure that the brackets do not slide out of alignment.

Once the brackets are clamped together use a cloth to wipe off the excess epoxy around the edges. The less epoxy on the top, bottom, and sides of the bracket the better. Let the brackets sit clamped together for 30-45 minutes to give them enough time to bond and cure.

You will wind up with some excess epoxy on the top, bottom, and sides even if you are extra careful. An easy way to clean the brackets up before you paint them is to use an angle grinder such as the Ryobi P421 with a wire cup brush attachment. Use the clamp to attach the bracket to a solid surface, then just run the wire cup brush over the bracket surface until all of the excess epoxy is removed.

You can also use a Dremel tool with a carbon or stainless steel brush attachment to remove the excess epoxy from the sides of the bracket.

After all of the excess epoxy is removed use a center punch or something pointed to clean out any epoxy from the 3 screw holes on each bracket.

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2. Prep and Paint the Mounting Brackets

Prepping and painting the mounting brackets is very similar to painting the radio mounting brackets as covered in part 2 of this series.

Since the brackets are mounted on the front fenders I wanted them to blend in with the rest of the Jeep’s body as much as possible, so I used a can of Mopar Body-Color Touch Up Spray Paint to get an exact paint match. If you are unsure of the color code for your Jeep check the sticker on the door jam on the driver’s side. It usually will include the factory paint color code or you can use this handy reference chart from Quadratech.

Before you paint the brackets, coat them with primer first. I used Rust-Oleum Clean Metal Flat White Primer (7780830).

NOTE: Only prime and paint the top and sides of the bracket. Leave the bottom side of the brackets unfinished so it can make a good ground to the Jeep fender.

The instructions on the can for the flat white primer and flat black protective enamel state to “hold can upright 10-16 inches from the surface and spray in a steady back-and-forth motion, slightly overlapping each stroke. Keep the can the same distance from the surface. Keep the can in motion while spraying. Apply 2 or more lights coats a few minutes apart.”

Follow these directions and apply 3 coats of primer.

Give the primer at least an hour to dry, and take the outside temperature into account as well. I painted the brackets in mid-July in Georgia and the temperature was well over 90 degrees. Don’t rush it, if the primer is still tacky when you touch it give it more time to dry.

Next, follow the directions on the Mopar touch up paint can and apply 3 coats to the top and sides of the bracket. The same thing as the primer applies to dry time. I let the paint try on the brackets overnight after all 3 coats of the Mopar paint were applied.

The last step is to coat the brackets with a clear top coat. I used Rust-Oleum Universal Dead Flat Clear Durable Topcoat (342482).

The instructions on the can for the dead flat clear coat state to “Hold can upright 8-12 inches from surface and spray in a steady back-and-forth motion slightly overlapping each stroke. Keep the can the same distance from the surface. Keep the can in motion while spraying. Apply 3 or more light coats continuously, spraying off the surface with each coat. For best results, apply multiple light coats versus one heavy coat.”

I applied 3 coats and let it dry four a couple of hours before installing the brackets onto the front fenders.

3. Mount the Brackets on the Front Fenders

Time to drill some holes in the Jeep (or whatever your rig might be). In general, the goal is to mount the antennas as far forward on the front fenders as possible.

The further the distance from the windshield and the rest of the body, the less the radio signal propagation from the antenna(s) is disrupted (theoretically). There is a physical limit to how far forward you can mount the brackets on the fenders while providing ample support and contact to the body. See the photos below for an illustration of where to mount the brackets.

As shown below, the right edge of the mounting bracket is right at ~5.5″ from the body at the firewall. You can test fit the bracket location by placing it on the fender, then sliding it towards the grille (front) of the Jeep to find the point where the bracket is still supported by the fender but is as far forward as possible as shown in the photo above on the right.

Once you have found the best mounting position for the bracket, mark the center of the 3 screw holes with a marker or something that will be easy to see.

To keep the mounting bracket in the position you marked, it is important to start the drill bit where the center of the hole should be (where you marked) to keep everything aligned. If the drill bit wanders off of the center of the hole, the bracket is either going to sit crooked or not fully contact the fender as you want it to.

Use a metal center punch to start the hole and help keep the drill bit in the correct place. Use the punch to make an impression on the fender where each of the mounting screw holes should be. This will help keep the drill bit at the center of the hole and from sliding around on the fender. When you start drilling the hole, rotate the drill bit slowly at first and then speed it up as the bit removes the metal..

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Use a 3/16″ metal drill bit such as the Milwaukee Shockwave Titanium metal bit to drill the 3 holes for the mounting screws.

Before you attach the bracket to the fender, remove a portion of the paint on the fender so the mounting bracket has a metal-on-metal connection which will create a good ground between the bracket and the body.

I used a Dremel tool with a carbon steel brush attachment to remove the paint. Carefully remove enough paint to match a width that is a little less than the width of the mounting bracket. You don’t want any bare metal on the fender to be exposed outside of where the bracket is mounted.

4. Mount the Bracket on the Driver Side Fender

Before you mount the bracket on the fender, run a bead of clear RTV silicone adhesive sealant around the portion of the bracket where it contacts the fender. This will help protect against rust or corrosion that is caused by water getting trapped underneath the bracket.

To secure the bracket to the fender, use 3 (per bracket) #10-32 x 1/2″ stainless steel machine screws. Place 3 star/external tooth washers on each screw between the bottom of the bracket and the fender. These will also help make a good electrical connection of the body. Secure the machine screws with 3 #10-32 stainless steel nylon locknuts on the underside of the fender.

5. Mount the Other Bracket on the Passenger Side Fender

Antenna Placement

Time for a little more antenna theory with regards to which antenna is mounted on which side of the Jeep. The Larsen NMO450CHW for the Midland MXT400 is mounted on the passenger side and the Larsen NMO2/70B for the Icom IC-2730A ham radio is mounted on the driver’s side.

Here is why – consider for a moment if both of the antennas were mounted on the back of the Jeep, say on the spare tire carrier as I originally mounted them.

If the antennas are too close together, there is a risk of the transmissions from one antenna being absorbed by the other antenna. Since these radios are capable of transmitting at 40 and 50 watts, if the transmissions from one antenna make it back to the radio connected to the other antenna there is a risk that the radio itself could be damaged by the RF energy. That absorption by the two antennas can impact the overall performance and range of the radios as well.

The idea behind mounting the Larson NMO450CHW on the passenger side is because that is the same side where the factory AM/FM stereo antenna is located on a Jeep TJ. The GMRS frequency band of 462/467 MHz is higher than the FM radio frequency band (~88-108 MHz), so it more or less will have less impact on the FM radio receiver in the Jeep.

The 2-meter ham frequency band of 144-148 MHz is closer to the FM radio frequency band, so putting the Larsen NMO2/70B on the other side (driver) of the Jeep puts it further away from the FM radio antenna. In turn, this (theoretically) reduces the chances of interference.

One thing to note however, given the power that both of these radios operate at it is possible that the FM radio could lose signal while talking on either the GMRS or ham radio. This has not happened to me, but I typically don’t have the FM radio on while either of the GMRS or Ham radios are in use.

6. Install NMO Mounts & Antennas

Now that you understand the “why” behind where each antenna is mounted, let’s move onto the installation.

I used Larsen NMOKHFUD NMO 3/4″ mounts which include the coaxial cable and no corrector forth both antennas. An important thing to note is that this type of NMO mount is typically designed to be mounted on the roof of a vehicle where the bottom side of the NMO mount and attached coaxial cable are not exposed to the exterior elements. Just the top/threaded portion of the NMO mount extends above the roofline where the attach is attached.

Given this design, it is important to make sure that the coaxial cable where it enters the NMO mount is properly sealed. If it isn’t, water can make its way inside the sleeve of the coax cable which will cause it to corrode.

Use a piece of marine-grade heat shrink tubing to seal the coax cable at the connector. Harbor Freight sells a good kit of 42 pieces of marine-grade heat shrink for only $5.99. The advantage of marine-grade heat shrink is that it has adhesive on the inside that melts when heated. This creates a good seal to protect against water. Cut a piece long enough to cover the metal connector and a portion of the coax as shown in the photo below. Heat it up with a heat gun until the heat shrink contracts and you can see the adhesive melt on the ends of the tube.

Unscrew the threaded part of the NMO mount and slide the base through the hole in the mounting bracket from the bottom. Re-attach the threaded part and the mount will fit snugly against the bracket. Use an adjustable wrench to tighten the threaded part slowly until it is snug.

7. Protect the Antenna Coaxial Cable

It is important to protect the coaxial cables for both antennas when you route them into the engine compartment. Cover the coax cable with 3/8″ plastic spiral wrap first. Use a zip tie to secure the spiral wrap in place where you start the run. Try and get it as tight as possible so the spiral wrap does not slip. If you have a hard time getting it try, consider using a zip tie puller/cutter tool.

Next, cover the coax cable with plastic split flex tubing and secure it in place with zip ties as well. This will give the coax cable extra protection as the cable needs to be routed around the sharp edge shown in the photo above to the right.

Attach enough split flex tubing so that the cable is protected right past the point where it enters the engine compartment – also see the photo above on the right as well. The edge is sharp and could potentially cut into the coax cable if not properly protected.

I found it was easier to pull the plastic weather stripping that is attached to the body/firewall back, then route the coax cable around the edge then push the weather stripping back into place.

Once you route the coax into the engine compartment do not run it to the point where it will pass through the firewall and into the cab. In part 4 of this series we will install a piece of high temperature braided sleeving that will protect the coax and power cables from high heat since it will be run close to the engine manifold. Just set the coax aside somewhere within the engine compartment where it will not get damaged

Close the hood and make sure it does not create a lot of tension on the coax cable when it is in the closed position. You may need to adjust the turn around the sharp corner to provide a bit more slack if it is tight. When the hood is closed it should look something similar to the photo below.

8. Label Both Antenna Coax Cables

IMPORTANT – Label both of the antenna coax cables so you know which cable/antenna goes with which radio. It’s easy to forget this once the coax cables are routed through the firewall and up to where the antennas are mounted.

For the labels, I used regular Avery 06141 file folder labels that you can buy on Amazon or at any office store. These labels have marks on each side, and I aligned those marks with the center of the coax cable (as best I could). Slide a piece of clear heat shrink over the label and heat it up for a nice, weatherproof seal.

9. Install the Antennas!

Now that the mounts are installed, attach the antennas to the mounts! Both antennas will come with rubber O-rings / gaskets that will protect against water getting in between the antenna base and the NMO mount. Place those O-rings around the mount then screw the antennas to the mounts. For the Larsen NMO450CHW I used the “super seal RGSS gasket” that it comes with. There is a paper insert in the package for the NMO450CHW that explains the difference between the two supplied O-rings.

Up Next – Part 4

Part 4 of this series will cover all things related to power for the radios. Running the power wiring, mounting the fuse blocks and the radio power cables so be sure to check it out next!

Thanks for stopping by Southeast4x4trails.com! If you are looking for a detailed guide on how to install a GMRS mobile radio or a mobile Ham radio in your Jeep or off-road vehicle you have come to the right place. Keep reading for more details about this 5-part series on my off road radio install project.

If you have found your way here via Google, this site is about the Jeep, 4×4, and off-road community in the Southeast US. Check out the home page for an interactive Google map of trails, off-road parks, forest service roads, points of interest and more in the GA, TN, NC, and SC areas. The Journal has other articles similar to this one on topics of interest such as “how-to” guides, trails and places to visit, and local history. The Resources page has many links to mapping, GIS, USFS forest areas, and technical info.

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This is the second in a series of 5 posts that detail the install of a Midland MXT400 MicroMobile GRMS radio and an Icom IC-2730A ham radio in my Jeep Wrangler TJ. You can adapt this information to any vehicle, it doesn’t have to be a Jeep TJ or even a Jeep!

This post will cover how I mounted both radios using a Smittybilt G.E.A.R overhead console and a set of custom made mounting brackets.

Part 1 includes a complete list of all the radio gear, tools, parts, and hardware that I used. The gear and parts that are used in this post are below as well.

If you want to jump directly to the install info just click one of the links below :

• Part 1 – Project Details, Gear, Parts and Tools
• Part 2 – Mounting the Midland MXT400 GMRS Radio and Icom IC-2730A Ham Radio
• Part 3 – Mounting the Radio Antennas
• Part 4 – Power, Wiring and Fuse Block Installation
• Part 5 – Radio Power Wiring and Antenna Coaxial Cable Installation

Before we get started I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items items listed in the post through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

Gear and Parts List

The following gear and parts were used in this post:

Radio Gear
■ Smittybilt G.E.A.R Overhead Console for Jeep TJ (5665001) – Extreme Terrain – Quadratec
■ Midland MXT400 MicroMobile Two-Way GRMS Radio – Amazon
■ Icom IC-2730A VHF/UHF Dual Band Transceiver (Ham Radio) – Amazon
■ Icom MBA-4 Controller Mounting Bracket – (For Icom IC-2730A) – Ham Radio Outlet or GigaParts.com

Hardware
■ Everbilt  #10-24 1.75″ Phillips Round Head Machine Screws (Qty: 2) – Home Depot
■ Everbilt #10-24 Flat Machine Screw Nuts (Qty: 6) – Home Depot
■ Everbilt #10 Inner Diameter (ID) x 5/16″ Outer Diameter (OD) x 1″ Aluminum Spacers (Qty: 2) – Home Depot
■ Everbilt #10-24 Nylon Lock Nuts (Qty: 2) – Home Depot
■ Everbilt Flat Aluminum Bar – 1″ (W) x 36″ (L) x 1/8″ (D) (Qty: 1) – Home Depot
■ Everbilt M4-0.7 x 15MM Socket Cap Screws (Qty: 4) – Home Depot
■ Everbilt M4-0.7 x 12MM Socket Cap Screws (Qty: 4) – Home Depot
■ Everbilt #8 Flat Nylon Washers (Qty: 24) – Home Depot

Paint & Primer:
■ Rust-Oleum Clean Metal Flat White Primer (7780830) – Amazon
■ Rust-Oleum Flat Black Protective Enamel (7776830) – Amazon
■ Rust-Oleum Universal Dead Flat Clear Durable Topcoat (342482) – Amazon

Tools
■ 7/32″ Milwaukee Cobalt Red Helix Hard Metal Drill Bit (48-89-2311) – Amazon
■ 5/32″ Milwaukee Cobalt Red Helix Hard Metal Drill Bit (48-89-4607) – Amazon
■ Electronic Digital Precision Caliper – Amazon (Optional)
■ Ryobi P340 One+ 18V Rotary Tool – Amazon (Optional)
■ Dremel MM485 Multi-Max Carbide Flush Cut Blade – Amazon (For Ryobi P340 Rotary Tool)
■ Ryobi P5231 One+ 18V Cordless Jigsaw – Amazon (Optional)
■ Bosch T121AF3 Jigsaw Blade for Metal – Amazon (For Ryobi P5321 Jigsaw)
■ Kreg KMA2900 Multi-Mark Tool – Amazon (Optional)
■ Harbor Freight Central Machinery 8″ 5-Speed Drill Press – Harbor Freight (Optional)

Radio System Guide & Wiring Diagram

The graphic below shows the entire radio system and how each component is connected and wired. All parts that are in front of the ‘Jeep Firewall’ box are mounted in the engine compartment. Click to download the diagram in PDF format.

Smittybilt G.E.A.R Overhead Console

The idea to base the radio mounts off of an overhead console came from the radio setup I had back in my first TJ, a 2000 Sport. Back then Tuffy Security Products made an overhead console that had 2 swing away doors that could be used to mount a CB. I also mounted my Icom IC-2800H ham radio on that overhead console and always liked the setup and where the radio display/controller was accessible but out of the way.

I came across the Smittybilt G.E.A.R overhead console while browsing parts one day, and figured it could be used to mount both the Midland MXT400 GMRS radio and the Icom IC-2730A ham radio I was planning to install. The console cover has an integrated MOLLE system (modular, lightweight load-carrying equipment) webbing that allows you to attach and configure MOLLE gear such as MOLLE pouches or attachments in a modular (however you want to) fashion.

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If this term sounds somewhat familiar you have probably seen in the military as that is where it originated and was developed. Basically, you can place the attachments in different configurations to suit your storage needs. The additional storage space is a nice plus in a Jeep where storage can already be tight.

The construction of the Smittybilt overhead console is very strong and rigid. It consists of an overhead “main frame” which is solid metal and a 600 Denier polyester/nylon cover that wraps around the main frame. The MOLLE straps/webbing are on the cover. It also comes with 6 different MOLLE style pouches and the necessary mounting hardware. The rear of the overhead console main frame attaches to the center of the Jeep’s roll bar using metal clamp sleeves. The front of the main frame attaches to the windshield and footman loop with metal brackets. See the installation instructions for more details on all the parts and components.

To start, install the overhead main frame but do not cover it with the nylon MOLLE wrapper. You will need to attach the Midland MXT400 mounting bracket first.

1. Mark and Drill Holes for the Midland MXT400 Mounting Bracket

To determine the position of the holes for the mounting bracket align the bracket on the overhead console frame so that the radio face will be angled towards the driver. This will set the angle of the radio correctly so that it faces the driver’s seat.

Hold the bracket against the overhead console frame with one hand and mark the position of the two holes shown on the bracket image below. Use a silver or other (similar) color Sharpie/pen to make the marks so they are easy to see against the black coating of the overhead console frame.

Next, use a 7/32″ drill bit that is suitable for metal to drill the first hole such as a Milwaukee Cobalt Red Helix Hard Metal bit. Using the Midland MXT400 mounting bracket, check the alignment of the hole by holding the bracket up and aligning the bracket with the hole. If you need to re-mark or adjust the position of the second hole, make a new mark while you are still holding the mounting bracket in place.

Note the lip on the side of the overhead console frame. This lip points down, which means that there is a gap between the top of the overhead console main frame and where the cover and MOLLE pouches actually sit when the cover is attached.

You can use aluminum spacers between the top of the overhead console frame and the Midland MXT400 mounting bracket to ensure a rigid installation of the bracket as shown in the steps below. This is important due to the constant vibration when driving off road – and so it isn’t generally annoying and bouncing around while you are on the trail.

2. Insert the Screws and Spacers for the Midland MXT400 Mounting Bracket

After you drill both holes, insert two #10-24 1.75″ Phillips round head machine screws from the top of the overhead console frame. Secure the screws in place by using 2 #10-24 flat machine screw nuts (on each screw – 4 total) as shown in the photo below.

Tighten the first nut against the bottom of the overhead console frame, then tighten the second nut against the first. Once both nuts are tightened, check to make sure the screw is secured in place tightly and there is no play or wobble. Again, as mentioned above this is important due to the constant vibration when driving off-road. You don’t want the radios shaking around as it can damage them as well.

Next, slide the two #10 Inner Diameter (ID) x 5/16″ Outer Diameter (OD) x 1″ long aluminum spacers over the two screws. Secure the spacers in place with two more #10-24 flat machine screw nuts.

3. Attach the Midland MXT400 Mounting Bracket

Now that the aluminum spacers are installed, place the nylon gear cover over the main frame and make sure it is tight using the velcro straps that attach on top of the overhead console main frame. You should be able to see the ends of each of the screws as shown below. Use a knife or other sharp object to make two small holes in the gear cover where the screws are located – just large enough for the end of the screw to pass through the cover.

Loosen the nylon gear cover and the two flat nuts that are holding the aluminum spacers in place. Slip the ends of both screws through the two holes you just made, then replace the flat nuts onto the screws from the outside of the gear cover. This will secure the aluminum spacers in place.

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It’s easier if you just loosen the gear cover enough to slip the screws through the holes instead of fully removing the cover then trying to re-attach it with the screws in place.

Use two #10-24 flat machine screw nuts per screw/spacer to secure the screws and spacers in place similar to the mounting screws in step 2.

You can now install the Midland MXT400 mounting bracket. Position it in place using the screw positions on the bracket as shown in step 1. Use two #10-24 nylon lock nuts to attach the bracket to the mounting screws. These nuts are vibration-resistant – they will help hold the bracket nice and tight against the mounting screws/spacers.

4. Test Fit the Midland MXT400

Test fit the Midland MXT400 in the mounting bracket and make sure everything is nice, tight and secure. There are 3 different screw positions on the rear of the mounting bracket that allow you to adjust the radio body in an up, neutral or down position. Try each and determine which position you like best.

5. Measure for the Icom IC-2730A Mounting Brackets

With the MXT400 in place, it’s time to make some custom mounting brackets for the Icom IC-2730A. As you can see in the photos in part 1 of the series, these custom brackets allow the Icom IC-2730A to sit directly under the Midland MXT400.

Before we jump into the details of how to measure for the brackets, let’s talk about materials. The brackets for the Icom IC-2730A are made out of solid flat aluminum bar stock that you can buy at Home Depot or a similar home improvement, hardware, or metal supply store. The idea for this project was to use materials that were readily available and did not require specialty metalworking tools other than those you might already have or can buy at home improvement stores. I don’t have that many metalworking tools, so that is the reason why I went with this approach.

I first attempted to make these brackets out of 2″ flat aluminum bar stock only to find out that they were too wide when all 4 brackets are mounted, so the final versions were made out of 1″ flat aluminum bar stock. Some of the photos below show the 2″ bar stock because those are the pictures I had for a given step, but the same concepts apply with regards to how to measure and make the brackets.

The 1″ bar stock is from Home Depot – Everbilt Flat Aluminum Bar 1″ (wide) x 36″ (long) x 1/8″ (thick). 1 bar is more than enough for the brackets.

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The easiest way to fabricate the brackets is to make paper templates first, then use the templates to mark and drill the holes in the brackets. To make this task a bit easier, the drawing below contains the exact measurements for the brackets that I made.

You can also download this template using the link below. I have set the PDF file to print to actual size, but I would suggest double-checking the measurements on the template after you print it and before you make any cuts. Using a pair of precision calipers will help make measuring quick and easy.

Template Download: Icom IC-2730A Mounting Bracket

6. Mark the Overall Dimensions on the Paper Template

The overall bracket dimensions are 3.5″ long by 1″ wide. Mark these dimensions on a piece of paper and cut it out. Also, mark the center of the template at 0.5″ (vertical – half the width of the template) on the top and bottom sides. If you want more space between the Midland MXT400 and Icom IC-2730A make the length of the bracket longer. If you use my bracket dimensions the two radios will be about 1/4″ apart at the front of the radio bodies where the displays are.

Ignore the width of the template in the photo below. It was for one of the 2″ wide brackets that I made.

7. Mark the Midland MXT400 and Icom IC-2730A Measurements

Next, align the template with the top of the Midland MTX400 radio body and mark the position of the mounting screw/hole. It should be about 0.7340″ (~3/4″) from the top of the radio body/paper template.

Measure from the center of the mounting screw/hole to the bottom of the Midland MXT400 radio body and mark that dimension on the paper template.

Decide how much space you want to have between the bottom of the Midland MXT400 radio body and the top of the Icom IC-2730A radio body (1/4″, 1/2″, etc). Measure that distance from the mark you made for the bottom of the Midland MXT400 radio body and mark it on the template. This mark will align to the top of the Icom IC-2730A radio body.

Now measure from the top of the Icom IC-2730A radio body to the center of the mounting screw/hole and mark it on the paper template. The distance from the center of the mounting hole to the bottom of the bracket should be 0.4375″ to the bottom of the bracket. Also, mark the bottom of the Icom IC-2730A radio body on the template as well.

Once all of your measurements are marked on the paper template, it should look pretty close to the photo below.

8. Test Fit the Paper Template

Both radios use M4-0.7 socket cap screws in the mounting holes. Use one of those screws to make holes in the paper template where the mounting screws are located. Just put something semi-rigid under the paper template and gently push the M4 screw through the paper to make a clean hole.

Next, carefully slide the paper template over one of the mounting screws on the Midland MXT400. Hold the Icom IC-2730A radio body in one hand and align the mounting screw hole with the bottom hole in the paper template and check for proper fit and the desired space between the two radio bodies. This is much easier to do with 2 people, but you can manage to do it with one person as I did.

9. Transfer Paper Template Measurements to the Aluminum Brackets

Make a mark at 3.5″ on the piece of Everbilt Flat Aluminum Bar 1″ bar stock and cut the first bracket. Since I don’t have many metal-specific cutting tools I tried several different tools to cut the brackets. I found that the best results came from using either a rotary cutting tool such as the Ryobi P340 with a Dremel MM485 Multi-Max carbide flush cut blade or a jigsaw such as the Ryobi P5231 with a Bosch T121AF3 metal blade.

Make a mark at 0.5″ (vertical – half the width of the bar stock) on the top and bottom of the bracket. Use your paper template and a straightedge to transfer the measurement marks from the paper template to the metal bracket. My favorite straightedge tool for tasks such as this is the very handy Kreg KMA2900 Multi-Mark tool.

10. Drill Holes for Mounting Screws in Metal Brackets

Similar to cutting the metal brackets, drilling the holes for the mounting screws in each bracket and keeping them in alignment can be a challenge depending on what tools you use. It’s important that all of the holes for the mounting screws align and are in the same position across all 4 brackets. If they are not aligned, the radio bodies will not sit evenly. You don’t want the holes to look like the photo below. This was one of my first attempts at the bracket and I tried to drill the holes with a regular hand drill.

The easiest and most consistent way to drill the holes is to use a drill press. I didn’t own one when I started this project but ended up picking up a Harbor Freight Central Machinery 8″ 5-speed drill press which is good enough for home and hobby use. As of the time of this post, it is on sale for $54.99 – which was worth it alone just to save the frustration of trying to drill the holes consistently using a hand drill.

You can simply secure the metal bracket piece to the drill press table, lower the press spindle and place the drill bit exactly where you want it. Drill the holes in one bracket, then use that bracket as a guide to drill the holes in the other 3 brackets.

Use a 5/32″ drill bit suitable for metal such as the Milwaukee Red Helix 5/32″ Titanium bit to drill the holes for the mounting screws.

If you do plan to use a hand drill, you can improve the accuracy of the holes by clamping the metal bracket to a piece of wood and securing it in place with a caliper or bar clamp as shown below. Drill the holes in the first bracket, then use it as a guide to drill the holes in the remaining 3 brackets.

I would also suggest using a metal center punch to help keep the drill bit in the correct place. Use the punch to make an impression on the bracket where both of the mounting screw holes are. This will help keep the drill bit at the center of the hole and from sliding around on the bracket. When you start drilling the hole, rotate the drill bit slowly at first and then speed it up as the bit removes the metal.

11. Test Fit the Mounting Brackets

Now that the brackets are cut and all the holes for the mounting screws are drilled it’s time to test fit the brackets. You will need 2 sets of the Everbilt M4-0.7 socket cap screws and 5 sets of Everbilt #8 flat nylon washers.

The width of the Icom IC-2730A radio body is wider than the radio body of the Midland MXT400. I used Everbilt #8 flat nylon washers to make the mounting brackets fit flush against both radios.

Gather the following hardware for each radio before you test fit the brackets:

Midland MXT400

• 4 Everbilt M4-0.7 x 15mm socket cap screws
• 20 Everbilt #8 flat nylon washers

Icom IC-2730A

• 4 Everbilt M4-0.7 x 12mm socket cap screws
• 4 Everbilt #8 flat nylon washers

Remove the mounting screws that came with the Midland MXT400. Attach each of the new mounting brackets using 4 nylon washers between the inside of the new mounting brackets and the outside of the Midland MXT400 mounting bracket. Secure each bracket in place with a nylon washer on the outside of the bracket and an M4-0.7 x 15mm socket cap screw, finger tight for now.

Hold the Icom IC-2730A radio body in one hand and attach it to the mounting brackets. Use a nylon washer on the outside of the bracket and M4-0.7 x 12MM socket cap screws. You do not need any nylon washers on the inside of the bracket.

Check for proper fit, alignment, and spacing once both radios are mounted. You can adjust the tilt angle of the Midland MXT400 by moving the rear mounting screws to different positions within the 3 notches at the rear of the Midland MXT400 mounting bracket (see the photo of this bracket at the top of the post) for reference.

Once you are happy with the fit, remove all of the mounting hardware. It’s time to prep, paint, and finish the mounting brackets.

12. Prepare and Paint the Mounting Brackets

I used the following primer, paint and clear topcoat:

• Rust-Oleum Clean Metal Flat White Primer (7780830)
• Rust-Oleum Flat Black Protective Enamel (7776830)
• Rust-Oleum Universal Dead Flat Clear Durable Topcoat (342482)

The instructions on the can for the flat white primer and flat black protective enamel state to “hold can upright 10-16″ from the surface and spray in a steady back-and-forth motion, slightly overlapping each stroke. Keep the can the same distance from the surface. Keep the can in motion while spraying. Apply 2 or more lights coats a few minutes apart.”

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The instructions on the can for the dead flat clear coat state to “Hold can upright 8-12″ from surface and spray in a steady back-and-forth motion slightly overlapping each stroke. Keep the can the same distance from the surface. Keep the can in motion while spraying. Apply 3 or more light coats continuously, spraying off the surface with each coat. For best results, apply multiple light coats versus one heavy coat.”

I followed those instructions and sprayed 4 coats (each) of the primer, flat black protective enamel, and clear topcoat. I did each coat about 30-45 minutes apart and then let the paint dry overnight before mounting the brackets. Keep the outside temperature in mind with regards to the dry time, it was July in GA (90+ degrees) when I painted them.

13. Prepare and Paint Nylon Washers

The nylon washers are white, so I painted them black so they blend in better with the black mounting brackets. This can be a little tricky – if you just set the spacers down on a surface and try to paint them the propellant from the spray paint will blow the washers all over the place. I used 4 pieces of blue masking tape and stuck each one of the spacers to the tape, then applied the primer and paint coats. I held the can further away from the washers when painting them to try and reduce the effect of the propellant.

Let the primer, paint, and clear topcoat fully dry before you remove the washers from the tape. I used the tip of a Xacto knife blade to gently lift each spacer and separate it from the tape so the paint did not peel away from the washer and stick to the masking tape adhesive.

14. Wrapping Up

Reassemble the radios, painted mounting brackets and painted nylon washers and you are done!

Up Next – Part 3

Part 3 of this series covers the installation of the radio antennas and mounting brackets so be sure to check it out next!

Thanks for stopping by Southeast4x4trails.com! If you are looking for a detailed guide on how to install a GMRS radio or Ham radio in your Jeep or off-road vehicle you have come to the right place. Keep reading for more details about this 5-part series on my radio install project.

If you have found your way here via Google, this site is about the Jeep, 4×4, and off-road community in the Southeast US. Check out the home page for an interactive Google map of trails, off-road parks, forest service roads, points of interest and more in the GA, TN, NC, and SC areas. The Journal has other articles similar to this one on topics of interest such as “how-to” guides, trails and places to visit, and local history. The Resources page has many links to mapping, GIS, USFS forest areas, and technical info.

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This is the first in a series of 5 posts that detail the install of a Midland MXT400 MicroMobile GRMS radio and Icom IC-2730A ham radio in my Jeep Wrangler TJ. You can adapt this information to any vehicle, it doesn’t have to be a Jeep TJ or even a Jeep!

This post will cover the background on the project, why I chose these 2 radios, and includes a complete list of all of the gear, tools, and parts that I used in this project.

If you want to jump directly to the install info just click one of the links below:

• Part 1 – Project Details, Gear, Parts and Tools
• Part 2 – Mounting the Midland MXT400 GMRS Radio and Icom IC-2730A Ham Radio
• Part 3 – Mounting the Radio Antennas
• Part 4 – Power, Wiring and Fuse Block Installation
• Part 5 – Radio Power Wiring and Antenna Coaxial Cable Installation

GMRS, FRS and Ham Radio

If you are not familiar with GMRS, it stands for General Mobile Radio Service. GRMS radios are widely used for short-to-medium distance two-way voice communication in the 462-467 MHz FM frequency range.

The use of GMRS/FRS radios in the off-road world has been growing every year. Simply put, these radios are a considerable improvement over older CB radios because they can operate at higher power levels (1-50 watts) and broadcast an FM signal. Higher power levels translate into much better voice quality and range (distance) as compared to CB radios, which operate on AM frequencies between 26-27 MHz at 1-4 watts. In fact, Midland is the official communications sponsor for the 2020 Jeep Jamboree USA. Jeep has also announced that all communications for the 2021 Jeep Jamboree USA will be on GRMS/FRS frequencies and no CB frequencies. This article about the Jeep Jamboree does a good job of outlining the key factors in the shift towards GMRS/FRS radios.

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Use of GMRS radios is licensed in the US by the FCC, but it doesn’t require a test like the Amateur Radio (Ham) services does. You can purchase a GMRS license directly on the FCC Universal Licensing System (ULS) website. The cost is $70 for 10 years and it covers anyone in your immediate family in addition to yourself. That means your wife/huband and kids can all legally operate GMRS radios under one license. You will be issued a call sign by the FCC when the license is granted (mine is WHRT850). Check out this page at ITS Tactical and Wikipedia for more info on GMRS radios.

FRS stands for Family Radio Service. FRS radios are permitted to transmit on the same frequencies that GRMS radios operate on. No FCC license is required to operate FRS radios, however. For more details about the difference between GMRS and FRS radios see the next section below – GMRS and FRS – What’s the Difference?

Amateur radio or “ham” radio is it is commonly known requires an FCC license (my call sign is KG4LNA) to operate legally. There are a number of different bands within the larger radio spectrum that are dedicated to ham radio operation. Two of the most popular bands are the 2 meter and 70 cm bands which someone with the entry-level technician license can operate on. The Icom IC-2730A radio featured in this post is a dual-band radio that can operate on both of these bands.

I mainly use my ham radio for backup and emergency communications. There are many ham radio repeaters around the country. If you are able to reach one of these repeaters while out on the trail or in the backcountry a repeater has the ability to re-broadcast (repeat) your signal at higher power and distance that you would be able to reach if just talking from one ham radio to another (simplex mode). To learn more about ham radio take a look at this page from the AARL.

GMRS and FRS – What’s the Difference?

GMRS and FRS radios share a total of 22 dedicated channels in the 462.5625 to 467.7250 frequency range. Each of these frequencies are labeled as a channel – 1 to 22. Both GRMS and FRS radios can operate on any of the channels, but the power output for FRS radios is capped at 2 watts for channels 1-7 and 15-22 and 0.5 watts for channels 8-14.

GRMS radios are capped at 5 watts for channels 1-7, 0.5 watts for channels 8-14, and 50 watts for channels 15-22. Channels 15-22 also permit the operation of GMRS repeaters which can greatly extend the signal distance and coverage if a GMRS radio has repeater capability. This is very similar to repeaters that operate on the ham bands as mentioned above.

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No license is required to operate on FRS channels/frequencies. FRS radios are also required by law to have a non-removable or fixed antenna and the radio cannot be modified to operate at higher power outputs than specified by the FCC for a given channel. FRS radios are often “walkie-talkie” types that are sold together as a pair. GMRS radios can utilize a non-fixed external antenna to extend their operating range. The following pages on RadioReference.com detail FRS and GRMS channel specifics and also have a combined channel chart.

Project Background and Details

This radio install project started with just the Midland MXT400 GMRS radio. I installed it in my Jeep and mounted the antenna on the tire carrier rear bumper. One Google search lead to another while I was doing the install, and after a couple of hours reading forum posts on RadioReference.com I came to understand that mounting any radio antenna on the rear of a Jeep Wrangler is not a good choice if you want to maximize the signal range, quality of your radio communications and the radio’s overall performance.

Why? Because typically there are multiple obstructions in the rear of Jeep (tire carrier, hard/soft top, other radio antennas, etc.) that affect the path and emissions of the RF waves that your radio antenna transmits. It alters the radio wave propagation pattern which means it impacts (makes it worse) the radio’s performance.

As I was doing my research on the best place to mount the radio antennas I posted a question on the Amateur Radio Antenna sub-forum on RadioReference.com. I was fortunate enough to have several very, very knowledgable, and helpful people respond to my post and help me figure out an installation plan that would be the best for my Jeep and communication goals. The simple install for the Midland MXT400 turned into a full-blown project and grew to include the Icom IC-2730A ham radio and even my Uniden SDS100 radio scanner.

Between the time that I spent researching the radios and associated gear, reading threads on forums, discussing the plan with others on the thread that I started on RadioReference.com I spent over 40 hours alone just planning out the entire installation project. This is before I even started the install work. This series of posts will walk you through each step of the install and will literally save you many hours of research and planning (and some frustration too). I’m sharing it for the benefit of others because I would have loved to come across the information as I put my project together.

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If you would like to read the original forum post and all the responses, take a look at Multiple Antenna Question for 2M/70CM. It also details information about the antenna install for my Uniden SDS100 scanner. You can also find more information about why mounting any antenna in the rear of a Jeep is not a good idea on this thread on jk-forum.com.

Why the Midland MXT400?

I have several handheld radios that are capable of operating on GRMS frequencies. These handheld radios often operate at a lower power output such as 4 or even 1 watt, and I knew that I wanted a GMRS radio that was capable of higher power output to maximize range on the trail. I also wanted a permanently mounted radio in the Jeep as well. After looking at several different mobile GMRS radios and reading reviews the Midland brand was showed up in many of the reviews or articles and the comments were generally favorable of their products.

The Midland MXT400 has a max output of 40 watts. It also does not require any programming. All of the GMRS and FRS radio channels are pre-programmed right out of the box. You simply turn the dial on the radio to set the channel you want to operate on.

It is also compatible with other radios (such as Midland’s) that can transmit on GMRS or FRS frequencies. If others in your group don’t have a GMRS license, they can use an FRS radio legally and the MXT400 will work seamlessly with those radios.

The MXT400 also has the capability to use PL Tone (CTCSS) and DCS codes. These codes are set to the same values on both radios, and the only way anyone else using the same frequency will be able to receive your communications is if they also have the same PL Tone or DCS code set that you are using. Midland refers to these codes as “privacy codes”. For more information on these codes see pages 17 and 26 in the MXT400 owner’s manual.

Why the Icom IC-2730A?

The Icom IC-2730A is a dual-band VHF and UHF radio. It can transmit at up to 50 watts on the 2-meter ham band (VHF) between frequencies 144-148 MHz and 70 cm ham band (UHF) from 430-450 MHz. It has dual watch/dual receive capabilities, which means that it can receive signals on either band simultaneously. This is useful if you want to stay tuned to a specific frequency such as a repeater or simplex (say a 2-meter frequency) but also want the ability to receive or scan frequencies on another band (say a 70 cm frequency). The radio has 2 sets of controls – one for each band (volume, squelch, etc.) You can scan a bank of frequencies that are programmed into the radio while the other frequency is stationary.

The IC-2730A also has a large channel memory at 1,000 channels. This was important to me as I have my IC-2730A programmed with both 2-meter and 70 cm repeaters in GA, TN, NC and SC. This adds up to about 800 different frequencies across all 4 states. I printed out a list of all the programmed channels along with their name and location, and I keep this with me in my Jeep. That way I don’t have to program the radio every time I go to a different state, I can just set the radio to scan mode for the bank of channels that are in the vicinity of my location.

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I compared several 2-meter/70 cm dual-band radios from other companies such as Kenwood, Yaesu, and Alinco and felt that the price and feature set of the IC-2730A was the best value. Several of these other radios were in the $300-$550 dollar range. The controller (display) on the IC-2730A can be mounted either on the radio main unit with the Icom MBA-4 or remotely from the radio main unit with the MBA-5 controller bracket and MBF-1 remote mounting base. I knew that I wanted to mount the controller display to the main radio unit, so I also purchased the MBA-4 bracket.

The display is also easy to see. The frequency numbers are large and visible at a glance. That was important to me as I mounted the radio just outside of my direct line of sight. Another plus is that the radio’s receive frequency range allows it to operate as a wideband receiver covering aviation, marine, and weather radio frequencies between 118-174 and 375-550 MHz. It is also fairly easy to program with a computer using the RT Systems USB-29A programming cable and WCS-2730 software once you get the hang of how the software works.

Wrapping Up

I am by no means a GMRS or Ham radio expert. I learned a lot (really, a lot) about radios, antennas, and electrical concepts in general throughout this project. I’m sharing what I learned with you and hopefully you will find it useful. If you have questions please post a comment and I’ll do my best to respond. The RadioReference.com forums are a great source of information and help as well.

I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items below through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

Radio Gear, Parts & Tools

Radio Gear:

• Icom IC-2730A VHF/UHF Dual Band Transceiver (Ham Radio) – Amazon – Ham Radio Outlet or GigaParts.com
• Midland MXT400 MicroMobile Two-Way GRMS Radio – Amazon or Midland
• Icom MBA-4 Controller Mounting Bracket – (For Icom IC-2730A) – Ham Radio Outlet or GigaParts.com
• Lind SDT1230-022 Shutdown Timer – Amazon – Lind
  • I bought two of these in new condition on eBay for $22.99
  • The normal retail price from Lind is $81.95
• Larsen NMO2/70B Antenna (For Icom IC-2730A) – Antenna Farm or Arcadian / Arc Antenna
• Larsen NMO450CHW Antenna (For Midland MXT400) – Antenna Farm or Amateur Radio Supplies
• Laird SBT3400 NMO Straight Antenna Mounting Bracket (Qty: 4) – Antenna Farm
  ■ NOTE: This straight-style bracket will NOT work with a Jeep JK or JL. You will need a JK or JL-specific bracket with a 3/4″ NMO hole such as this one from Antenna Farm or Topsy Products.
• Larsen NMOKHFUD NMO 3/4” Antenna Coaxial Cable w/ No Connector (Qty: 2) – Antenna Farm or Arcadian / Arc Antenna
• RFI RFU-505-ST PL-259 UHF Crimp Style Coaxial Cable Connector (Qty: 2) – Antenna Farm or Ham Radio Outlet
• Smittybilt G.E.A.R Overhead Console for Jeep TJ (5665001) – Extreme Terrain– Quadratech
  • This console is also available for a Jeep JK
• Magnetic Mic Radio Microphone Mount (Optional) – Amazon

Tool List:

NOTE: This is a list of the specialty tools that I used for the install. Other common tools (drill, screwdrivers, etc.) are required as well.

• IWISS Ratchet Crimping Tool Set w/ 22-10 Gauge Wire Die – Amazon
  • This tool is for the smaller 10-22 AWG gauge wire terminals
  • You can also use a fixed crimping tool like the Klein Tools 1000 – Amazon
• Fryic Ratchet Crimping Tool for 20-7 AWG Wire – Amazon
  • This tool is for the larger 8 gauge wire terminals
• LP DL-801G Ratchet Crimping Tool for RG58 Coaxial Cable – Ham Radio Outlet
• TerraWave HT-312B RG-58 Coaxial Cable Stripper – Antenna Farm
• Wagner Spraytech 0503008 HT1000 Heat Gun – Amazon
• AstroAI DM6000AR Digital Multimeter – Amazon
• Surecom SW-102 S0239 Digital SWR Meter – Amazon
• Antenna Farm 8219-3-PL259-C 3 Foot RG-58 Coaxial Jumper Cable – Antenna Farm
• Milwaukee 1-1/4” Hole Dozer Hole Saw Drill Bit (49-56-9664) – Home Depot
• Milwaukee 48-89-4607 Shockwave 5/32” Titanium Drill Bit – Amazon
• Milwaukee 48-89-4609 Shockwave 3/16″ Titanium Drill Bit – Amazon
• Milwaukee 48-89-2311 Red Helix Hard Metal 7/32″ Cobalt Drill Bit – Amazon
• Dremel Rotary Tool – Amazon
• Dremel 428 Carbon Steel Wire Brush – Amazon
• Wera PH0 Precision Screwdriver – Amazon
• Xacto Black Gripster Knife – Amazon
• Ryobi 9340 Rotary Tool – Amazon
  • Tool cut aluminum/metal brackets
• Dremel MM485 Carbide Flush Cut Oscillating (Rotary) Blade – Amazon
  • Rotary blade/bit to cut metal brackets
• Ryobi P5231 Jigsaw – Amazon
  • Second tool option to cut aluminum/metal brackets
• Bosch T121AF3 Metal Jigsaw Blades – Amazon
  • Jigsaw blade/bit to cut metal brackets
• Kreg KMA2900 Multi-Mark Multi-Purpose Marking and Measuring Tool – Amazon
  • One of my favorite mark/measure tools – for transferring measurement marks from paper template to aluminum/metal brackets

Parts List:

• Daystar Universal Firewall Boot (KU20040BK) – Amazon – Quadratech
• Insultherm High Temp Braided Sleeving – 1.5″ and 5/8″ Diameter – Wire Care
• Blue Sea Systems ST Blade ATO/ATC Fuse Block (6 Circuit w/ Negative Stud Terminals ) (5025) – Amazon
• Blue Sea Systems Maxi Fuse Block / In-Line Fuse Holder (5006) – Amazon
• WindyNation 8 AWG Gauge Pure Copper Flexible Cable Wire – 30 Feet, Red (Battery Positive) – Amazon
• Windy Nation 8 AWG Gauge Pure Copper Flexible Cable Wire – 15 Feet, Black (Battery Negative) – Amazon
• Belden 14 Gauge Primary Wire in Red, Black (25 Feet) – NAPA Auto Parts
• Selterm Heavy Duty Bare Copper Terminals for 8 AWG Gauge Wire, #10 Ring Stud – Amazon
• Selterm Heavy Duty Bare Copper Terminals for 8 AWG Gauge Wire, 1/4” Ring Stud – Amazon
• Blue Sea Systems 30 Amp Maxi Fuse (5138) – Amazon
• NAPA Auto Parts In-Line Mini Fuse Holder (784667) – NAPA Auto Parts
• Blue Sea Systems Contura II Off-(ON) SPST Switch – Amazon
• Littelfuse ATO 15 Amp Smart Glow Fuse (Qty: 2) (0AT0015.VPGLO ) – Amazon
• Littelfuse 5 Amp Mini Fuse (0MIN005.VP) – Amazon
• Dorman 16-14 Gauge Butt/Crimp Connectors (85436) – Advance Auto
• Dorman 16-14 Gauge 1/4″ Ring Terminal (85409) – Advance Auto
• NAPA Auto Parts 16 to 14 Gauge Step Down Butt/Crimp Connector – NAPA Auto Parts
• MaxBrite 16-14 Gauge Fully Insulated Female Disconnect Terminals – Amazon
• Ideal Ground Screws (774042) – Home Depot
• Tyco Electronics Raychem #10 Heat-Shrink Spade & Ring Terminals for 16-14 Gauge Wire – Home Depot
• Storehouse 42 Piece Marine Heat Shrink Tubing (Qty: 2) – Harbor Freight Tools
• XHF 160 Piece Clear Heat Shrink Tubing – Amazon
• Gardner Bender 3/8” & 1/2” Electrical Split Flex Tubing (FLX-538C10) – Home Depot
• Gardner Bender 3.5 Foot Wire Spiral Wrap (FLX-538C10) – Home Depot
• Permatex Clear RTV Silicone Adhesive Sealant (765-1344) – Amazon
• Gorilla Glue Clear Epoxy (4200101) – Amazon
• Gorilla Glue Heavy Duty Mounting Tape – Amazon

Hardware List:

• Everbilt #10-24 1.75″ Phillips Round Head Machine Screws (473684) – Home Depot
• Everbilt #10-24 Aluminum Machine Nut Screws (809048) – Home Depot
• Everbilt #10-24 Stainless Steel Nylon Lock Nuts (800121) – Home Depot
• Everbilt Flat Aluminum Bar 1”x36”x1/8” (887480019377) – Home Depot
• Everbilt #10 ID x 5/16” OD X 1” Long Aluminum Spacers (596-680) – Home Depot
• Everbilt M4-0.7x10MM Socket Cap Screws (574-128) – Home Depot
• Everbilt M4-0.7x12MM Socket Cap Screws (574-145) – Home Depot
• Everbilt M4-0.7x15MM Socket Cap Screws (564-012) – Home Depot
• Everbilt #10-32×1/2” Stainless Steel Round Head Machine Screw (Qty: 6) (476-222) – Home Depot
• Everbilt #10-32 Stainless Steel Nylon Locknut (Qty: 6) (317-647) – Home Depot
• Everbilt #10 Stainless Steel External Tooth Washer (Qty: 6) (597-540) – Home Depot
• Everbilt #8 Flat Nylon Washer (595-030) – Home Depot (Radio Mount Spacers)
• Everbilt M4-0.7 X 8MM Phillips Flat Head Screw (574629) – Home Depot
• #6 x 5/8 Self Tapping Screws – Amazon

Paint & Primer:

• Rust-Oleum Clean Metal Flat White Primer (7780830) – Amazon
• Rust-Oleum Flat Black Protective Enamel (7776830) – Amazon
• Rust-Oleum Universal Dead Flat Clear Durable Topcoat (342482) – Amazon
• Mopar Body-Color Touch Up Spray Paint – Quadratech

Up Next – Part 2

Part 2 of this series covers how I mounted both radios using a Smittybilt G.E.A.R overhead console and a set of custom made mounting brackets.

Parts List:

• ATOTO A6 Double-DIN Android Car Navigation Stereo – A6Y2710SB – Amazon – ATOTO ($164.90)
• Metra Jeep Wrangler TJ Double-DIN Dash Kit – 95-6541 – Metra – Crutchfield ($99.99)
• Metra Jeep Wrangler TJ Wiring Harness – 70-6502 – Amazon – Metra – Crutchfield (14.99)
• Metra Jeep Wrangler TJ Antenna Adapter – 40-CR10 – Amazon – Metra – Crutchfield ($9.99)
• Crutchfield Master Sheet / Install Guide & Wiring Adapter Guide- 027 0017 & 120 70-6502- Crutchfield (Optional) ($9.99)

Before we get started I’d like to ask you for a favor. If you find this post useful please consider supporting this site by purchasing any of the items above through the links provided. The links to Amazon are affiliate links, and the small commission that I may earn keeps this site running so I can continue to provide helpful information.

My TJ is a 2004 model year.

Instructions

1. Connect Wiring Harness(es)

Connect the Atoto A6 wiring harness to the Meta Jeep TJ wiring harness. The colors on both harnesses match up almost 100%.

Use 22-18 gauge wire connectors/crimps. I also used 1/8 – 1/4” heat shrink tubing to protect the connectors in case they get wet. Simply match the wires below from the ATOTO harness to the Metra harness and connect them with a wire connector/crimp. Cut a piece of the heat shrink tubing long enough to cover the wire connection and a portion of the wires on either side of the connector. Put the heat shrink tubing on a wire first before attaching with a wire connector.

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You may use some of the wires in the “Not Used” section such as the Rear Camera or Parking Brake depending on which accessories you install. These are the wires that I did not use on my install.

2. Remove Center Dash Bezel

Carefully remove the center dash bezel. If you have not removed it before you can easily find instructions online or you can purchase the Crutchfield MasterSheet which provides step by step instruction on how to remove the center dash bezel (link above in the parts list).

You also will need to re-use the existing air (heat and A/C) vents from the original dash. To remove both vents, gently push them from the inside of the bezel until they slide out. They are held in place by a grooved recess on both sides of each vent. Once they are removed, transfer both vents to the new Metra double-DIN dash by inserting and pushing them into place from the outside of the bezel.

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TIP: When you pull the center dash bezel off pull it slowly so you do not damage the 4 retaining clips that keep it attached to the dash. Once the bezel is removed, pull the 4 clips off of the bezel and set them aside. You will reuse them when you install the new Metra double-DIN dash bezel.

3. Remove Radio

Remove the 4 screws that retain your existing radio. Detach it from the existing wiring harness and remove the antenna connector.

4. Detach the Heat and A/C Control Bezel

Remove the screws that retain the heat, A/C and fan controls. Gently pull the assembly forward. You want it to be as out-of-the-way as possible while trimming the dash pieces so the double-DIN stereo will fit.

I did not detach any of the plugs that attach to the controls on the bezel.

5. Test Fit the ATOTO A6 in the New Metra Double-DIN Dash Bezel

Make sure the ATOTO unit fits snugly in the new Metra double-DIN dash bezel and check that there are no gaps between the outer edge of the ATOTO unit and the dash bezel. It fits very well, so you should not have any issues.

6. Remove the Lower Tray / Support

You will need to remove the plastic lower tray to make room for the ATOTO unit.

Start by pushing the wires that are towards the rear of the dash as out-of-the way as you can. Take your time while cutting the plastic and be EXTRA CAREFUL to not cut or nick any of these wires.

Start by cutting the right side first. I used a small hack saw instead of a powered device so I could go slowly and make sure I didn’t hit or cut any of the dash wires. Cut the “top” or “flat” part first as shown in the photo below.

Once the top/flat piece is cut, then cut at an angle to remove the remaining piece of the tray.

These photos give you another view of the angles to cut and what it looks like once the cuts are complete:

Repeat the process on the left side of the lower tray. Notes that one of the wiring harnesses attaches to the back of the tray on the left side. Disconnect the plastic retaining clip and push the harness as far out of the way as you can.

Depending on your cuts, you may need to do some final trimming once the lower tray is removed. Note the areas in the photo below that are not completely cut.

Once both sides are cut, remove the tray and it will look like this:

7. Remove Upper Plastic Support

My TJ is a 2004 and it also had a plastic piece above the radio that appears to have helped stabilized the factory stereo unit. I attempted to test fit the ATOTO unit without removing this piece, but it would not fit properly as the two tabs towards the rear of the piece pushed the ATOTO stereo down and the mounting holes would not line up properly.

I used a Dremel tool with a cut-off attachment to first remove the two tabs to see if that was enough (it wasn’t, read on):

After the two tabs were cut off, I switched to a Ryobi rotary tool with a cutting blade to make the remaining cuts:

And it should look similar to this once the top piece is removed:

8. Attach Mounting Brackets to ATOTO Unit

The Metra double-DIN dash kit comes with the required 2 mounting brackets for a double-DIN size stereo. I tried probably 10 different bracket and screw placements before I found the combination that allowed the ATOTO unit to fit just right in the dash and line up with the new dash bezel.

Here is the final bracket and screw placement that I used:

Note that the mounting brackets will extend slightly below the bottom of the ATOTO unit. The brackets also rest on top of 2 screws on each side of the unit.

9. Test Fit the ATOTO Unit and the Metra Double-DIN Dash Bezel

Before you plug in all of the wires and connections, place the ATOTO unit into the dash and secure it with the mounting screws. Make sure that it fits nice and easy with no resistance — you should be able to slide it in with one hand and line up the mounting brackets with their screws. If you are not able to then you most likely need to do some more trimming of the plastic pieces.

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You may need to position the screw holes on each side of the Metra mounting brackets one at a time. For example, attach the upper left screw first, then do the same for the others until all 4 screws are lined up and tightened.

TIP: Do not attach the retaining clips that you removed from the original dash bezel to the new Metra dash bezel yet. This makes it easier to slide the center bezel on and off if you need to make fit adjustments.

10. Connect All Wiring and the Antenna

After you have test fit the ATOTO unit, remove it and connect all of the wiring and the Metra antenna adapter. You will have connections for the ATOTO wiring harness, the USB input cable, GPS antenna and Wifi antenna.

11. Run Wires for the GPS and WiFi Antennas

I placed the GPS and Wifi antennas on the windshield right above the the top dash trim piece. This keeps them out of the way, but also provides good reception. I cleaned the area on the windshield where I attached them with an alcohol wipe pad first.

I have also heard of others installing these two antennas on the heat/air vents that are right under the center dash bezel if you prefer to have them hidden from sight.

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12. Re-Install the ATOTO Unit and the Metra Dash Bezel

Reinstall the ATOTO unit once all wires are connected. Attach the dash retaining clips to the new Metra double-DIN center dash bezel and re-install all of the dash trim screws.

And you are done! The photo at the top of the post shows the completed installation.