Offroaders take their rigs and gear seriously — especially their trail comms. The MicroMobile MXT275 is ideal for overlanders who need effortless communication while they navigate technical terrain. Our friends Mike and Sidney outfitted their 2017 Toyota 4Runner TRD Pro–Dumbo the Rig–with a custom GMRS radio installation. Their seamless install was completed on a 5th-generation 4Runner, but with the principals of this GMRS radio installation can applied to virtually any vehicle.
Once you’ve installed your MicroMobile, head out to one of these off road trails.
Step-by-Step Instructions for a Super Clean MicroMobile GMRS Radio Installation
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We originally used a CB radio for our trail comms. However, we were not a fan. Once the CB was installed, we were less than impressed with the setup. We were disappointed in the range and the inconvenience of tuning the radio. It left the inside of our rig messy with the handsets always out, plus the big floppy antenna was constantly hitting things – it just was not what we wanted. We decided to switch to the MicroMobile.
The idea for a cleaner GMRS radio installation that fit our needs better came a few months back when I helped a good friend of mine install their two-way radio. While most of this mirrors that install, we did we change a few things for our application, needs, and desires. We’ve provided the steps of our install, but feel free to tailor to suit your rig and communication needs.
The Plan for Our MicroMobile Install
Being able to completely stow the main unit and mic along with controlling the power output were important customizations for us. We decided, instead of putting the GMRS on a switch as most do or just making it a constant power ON, we would put a constant hot 12V outlet near the control unit so it can be powered when we want and off power when we don’t. This would also allow us to also put in other 12V powered accessories when not using the GMRS radio.
We wanted a seamless look and to keep the control unit out of the way, so we decided to put the control unit in the glove box. This would allow all of the wires to be routed behind the glove box–giving us the cleanest possible look we could ask for.
The fully integrated mic is a big reason for using the Midland MXT275 because the control unit can be stashed out of the way. Our GMRS radio installation needed an extended mic connection to avoid having to leave the glove box open or crush the wire when closing the box. This is where the RJ45 Coupler came into play. The result was the cleanest install possible, leaving the dash seamless and functional.
1. Midland MXT275 MicroMobile® two-way radio
2. Browning BR-450 Antenna
3. K400SNMO Trunk/Hatchback Antenna Mount
4. RJ45 Waterproof Coupler Socket Connector – this is the connector used in the dash to make the handheld connect into the dash versus the control unit. This leaves the dashboard seamless when the handheld is removed and stored when not in use.
5. Cat.5E Cable – we extended the microphone jack on the control unit to the RJ45 coupler. The 3’ cable worked in our application–other applications may need to be longer.
6. Nite Ize Steelie® Original Dash Mount Kit – we went with this option so we could attach our phone when not using a handheld.
7. 12V Blue Seas outlet – this is a fused constant hot power source
8. Ancor 12 AWG Primary Wire
9. Ancor 12-10 AWG – female fully insulated nylon disconnects
10. Heat Shrink
11. Ring Terminals of your size choosing depending on the application
12. Wire Sheathing
13. NMO Dust/Rain Cap
14. Zip Ties
- 10MM socket
- Ratchet wrench
- Step drill bit (minimum 7/8 – 1-1/8) or a 1-1/8 drill bit
- Flathead screwdriver or plastic pry tool
- Wire crimping tool
- Wire stripping tool
- Heat gun or torch
- Dremel w/ plastic cutting blade
- Fish tape or a wire hanger
- Stubby Phillips head screwdriver
How To Install Your MicroMobile GMRS Radio
Now that you have all the parts and tools, here are Mike and Sidney’s step-by-step instructions for their squeaky clean GMRS radio installation in their 4Runner.
Step 1: Disconnect the Power
First thing first, SAFETY. You’ll start this process no different than doing any other work on your vehicle by disconnecting the power to your vehicle.
In this case, especially, we knew we wanted all the wiring to be behind the glove box. On a 5th Gen 4Runner, that means that the passenger-side knee airbag will have to move. We started with the POWER DISCONNECTED and began removing panels.
Step 2: Remove Panels
Next, we removed the passenger side kick panel and the other associated panels. While removing the interior panels you will find there is a small little cover on the lower left side on the bottom of the glove box that you must remove concealing one of the 3 bolts securing the airbag. Keep this small cover close; this is where we chose to put the RJ45 coupler (see pictures for reference).
Step 3: Move the Airbag
With all the panels removed, you will now have access to the three 10mm bolts securing the passenger-side knee airbag. Once you remove the 3 bolts securing the passenger-side knee airbag, you will have to pull on it as it is secured with plastic clips to the bottom of the glove box (I found starting from the door side and working toward the center of the vehicle worked best for me popping each clip one by one).
Once the airbag was free, I did not disconnect it. Personally, I am not a fan of playing with airbags, so I simply moved it and set it down in the footwell where it would no longer be touched.
Step 4: Remove the Glove Box
With the airbag out of the way you will now have access to the two 10mm bolts securing the bottom of the glove box, which you can now remove. Next you will need to pop open the glove box and using either a flat head or your plastic pry tool remove the 3 plastic covers concealing the 3 upper mounting bolts. Once the mounting bolts are removed, the glove box should come out easily by pulling on the top and bottom simultaneously. There are 2 plastic clips that hold the wiring for your glove box light in place. Press the sides of the clips in and remove the light to free the glove box from the vehicle completely if you’d like space to work.
Step 5: Outfit Glove Box with Outlets
Now with everything removed, we can assemble the glove box and prepare it.
In the glove box, there are 2 covers on the left side a circular one which looks like a 12V outlet belong and a rectangular one. Both covers can be removed by pressing on the tabs on the back of them which you will need to do. The circular cover can be discarded or saved since the Blue Seas 12V outlet will take its place and the rectangular cover will need to be kept.
With the covers removed you will now need to drill out the circular hole with the 1-1/8 drill bit or step bit in order to fit the 12V Blue Seas outlet. You won’t be drilling much–just enough to fit the outlet. Once drilled, install the Blue Seas outlet.
Now take the rectangular cover and use a Dremel to cut a pass-through for your 12V power socket from the Midland MXT275. The MicroMobile power socket has a disconnect, so the pass-through only needs to be big enough to pass the connector through. The inline fuse can be easily taken apart and reassembled once through the pass-through you cut out. Then reinstall the rectangular cover to the glove box with the 12V socket through it.
Step 6: Run Power to Outlet
You will want to figure out how you are going to get power to the 12V outlet. It was important to us to have an “always-on” socket to power the radio when needed as well as provide another 12v power outlet when not using our GMRS radio. We already had a Power Tray unit installed on our vehicle which holds a Blue Seas 6 circuit fuse block, so we ran our power from there. The Power Tray added the necessary fuse for the 12V outlet, but we needed to extend the mic cable.
Next, we measured out our desired wired length based on our fuse block position and put sheathing on our wires. We used #8 nylon insulated ring terminals and connected to the fuse block (remember power is disconnected still). Then we ran the positive and negative wires along the back firewall and through the main grommet on the passenger side firewall with fish tape (if you can, try and pull the wires and the antenna cable through at the same time if you plan to run the antenna through this grommet as well). Once the wires were through the firewall and routed how we wanted, we secured it all in place with a crimped 12-10 AWG female fully insulated nylon disconnects that connected it to the back of our 12V Socket.
Don’t install the glove box or connect anything just yet since we will still be working with the glove box.
Step 7: Mount the Antenna
Mounting the antenna is straightforward and is completely up to the user for placement. We chose the hood; if you choose this as well, make sure to check your clearances and make sure the mount doesn’t rub the fender and the set screws are nice and tight. You’ll route the cable through the same grommet if you haven’t already with the wires and route and secure the cable as you’d like. Pull the excess cable through the grommet and bundle nicely and secure it away from anything that will pinch it and tuck it behind the glove box when reinstalling.
Step 8: Mount and Connect the Main Unit
Moving onto mounting the main unit, this is up to you for placement within the glove box. The Midland main unit has a mount and comes with mounting screws to secure it. To maintain a clean dash with as little wiring visible as possible, we knew we wanted the main unit out of sight and out of the way.
We drilled a hole through the right side of the glove box which allowed the antenna cable, power cable, and the 3’ Cat.5E Cable to be passed through. Next, we also drilled the hole large enough for the connectors to protrude through which would allow the main unit to sit flush up against the side of the glove box and the cables/wires to not be seen inside the glove coming off the back of the unit.
We reinstalled the glove box light and put the clips holding the wires back into their respective places and then we secured down the mount for the main unit with a stubby Phillips head screwdriver with the provided hardware. We connected our antenna cable and then secured the power wired for the main unit along the wires for the glove box light and connect the positive and negative wires to their respective positions on the back of the 12V outlet. Be sure to heat shrink and seal all connections.
Step 9: Connect Antenna Cable and Power Wires
We connected our antenna cable and then secured the power wired for the main unit along the wires for the glove box light and connect the positive and negative wires to their respective positions on the back of the 12V outlet. Be sure to heat shrink and seal all connections.
Step 10: Install Coupler for the Mic
With everything connected (power to the 12V Outlet, Antenna cable to the back of the main, and the power for the main unit) you can then connect the Cat.5E cable to the front of the main unit and you will want to run the 3’ cable through the same hole as the antenna and other connections and then reinstall the glovebox and airbag in reverse order from the beginning. Run the Cat.5E cable down and across the back of the airbag to where the RJ45 coupler will be. Next, grab the small cover concealing the bolt we removed at the beginning and utilizing your step bit again, find where you would like your RJ45 Coupler to sit and slowly drill the hole to fit the coupler. Use the provided hardware and secure the coupler in place connect the Cat.5E cable to the backside and reinstall the cover onto the vehicle ensuring the cover is fitting properly.
Step 10: Reattach Panels and Install Mic Mount
Once done, reinstall all panels removed back onto the vehicle in reverse order and clean the area. Make sure you attach the antenna to the mount and then connect the handheld unit to the RJ45 coupler and ensure there is power to the handheld unit and that it works. I hit the weather button and ensured the transmission was clear. You can now decide the placement of you Nite Ize mount. I removed the mic clip on the back of the handheld unit and put the flat portion of the Nite Ize mount there with a drop of RTV to ensure it wouldn’t fall off. I would also suggest getting a cover for the antenna mount if you take the antenna off and on.
You now have a very clean GMRS radio install you can have out when you use it or stowed away when being a grocery getter. Want more custom dashboard inspiration? Check out Taco Pro Matt’s custom MicroMobile install in his 2017 Toyota Tacoma.