Tek Net
March 26, 2023
"Installing your mobile radio, Tip..Tricks & and how to do it"
This weeks topic was requested by one of our regular participants on the Tek Net.
I will be passing on a few tips that has helped me over the past 40+ years in the two-way radio business.
You need a plan:
Most mobile installations consist of three parts, (1) Antenna mounting, (2) Radio/ Control Head mounting, (3) Electrical wiring.
Stepping back and visualize where you want to do the these three things will help to not create a snag in your installation.
For example, what do i need to temporarily remove to accomplish my install ( like remove the front seat, pull back the carpet, etc.).
Where will I run the power lead in the engine compartment?
Where is the antenna going to be mounted?
The vehicle we will be installing the radio in is a 4-door Lexus ES300 with an electric sunroof.
The first item, will be running the cable from the radio (in the trunk area) to the control head in the drivers compartment.
Also getting the speaker wire under the carpet to the area of the front passenger kick panel (speaker location).
To make the cable routing from the radio to the control head easier, it will require that I remove the passenger seat. This is done by removing the four bolts holding the seat slide track in place and the disconnection of two electrical connectors under the seat, then lift it out and place it out of the way for now.
Here you can see that the seat was removed and that there are several cuts in the carpet for the seat wiring , that we can take advantage of to route our cable to the control head.
Note: This particular radio has the control head built into the microphone ( an older Motorola Spectra radio often used by the FBI in unmarked vehicles.
If you have a Kenwood or Icom radio with a separate head, just place the head where you need to and route the cable from the radio T/R package in the trunk to it.
The RED wire that can be seen above is the Ignition sense wire. It will be connected to the Cigar lighter jack in the bottom of the Console glove box, this way the radio comes on and off when the vehicle is in use and never runs the battery down because the radio was left on.
Here I removed the bottom rear seat cushion, by pushing in the front of the seat frame and lifting it up at the same time.
If it doesn’t want to let go, more force is needed to push the frame back (that’s when i called my grandson to assist).
You can see the cables from the front, the control cable to the head/microphone and the power lead going to the engine compartment.
We will cover getting the power lead through the fire wall later.
Almost out of view to the left, the plastic door molding has been lifted off to release the carpet, do this to the front door molding also, this releases the carpet so that the cables can be run under the carpet to the trunk and allows the wires from the engine compartment and the speaker wires to be run under the carpet.
Next: getting the power lead thru the firewall into the front compartment area.
Now that I made about a 1/4″ slit into the rubber grommet, don’t go too deep but just big enough to get the rod and wire thru.
I can feel the rod touch something inside, probably the back of the heater or glove box.
By moving the rod around a bit, it cleared the obstruction and was able to be found.
Now that the engine compartment wiring is done, time to mount the radio in the trunk and the antenna.
The antenna will be mounted on the vehicle’s trunk lid.
Normally I would install on the roof for the most ideal location, however the electric sunroof prevents me from doing that.
I’m installing a NMO (stands for New Motorola mount) on the center of the trunk lid. After removing the cover panel’s snap plugs…it was a snap.
There is so many videos on You Tube on how to install the NMO mount I decided to not show pictures of the mounting except the pieces and installed antenna below.
I do suggest that you watch a video if you plan on doing your own antenna mount.
