2-way radio installation

I’d appreciate any (dis)recommendations,

especially (but not exclusively) from any

others who have installed 2-way radios.

The RF wiring is my primary unknown.

I’m equipping a newly-acquired (hand-me-down) car

for 2-way radio (aviation, gmrs, 2m, …).

I’ve equipped a dozen or so vehicles in the past.

This will be my first vehicle with neither

radio-transparent (i.e. plastic) sides nor

pre-wired receiver antenna mount.

As time and ease of disassembly permits,

I’m considering routes and fabrication

difficulties, with the full service manual,

and hints from my local Toyota dealer.

I don’t believe I can use the in-glass antenna.

Though 1970s car service manuals had no

instructions for 2-way radio installation,

more recent Saturn and Chrysler service manuals

had nearly complete instructions, surprising

absent from the recent Toyota service manual.

At this time, the car has been modified

(reversible splice at Driver Side J/B)

to continuously energize (for typical engine

off use) the cigarette lighter and floor console

power outlet jacks. To protect the ECUs, an RF

filter is reversibly inserted inline at a

connector (IO1) under the center console box.

The connector (and Floor Wire 3) have no

apparent purpose (for assembly, disassembly,

…) other than as filter install site.

The remaining problem is how to install an RF

female (F?) connector within easy access of the

center console box or passenger seat, a

transmitter antenna mount (SMA?, BNC?) on the

trunk lid (or roof?), a rubik-cube-sized box

(impedence matcher) for quarterly maintenance,

and pull (push? reuse?) RF cable (RG-58?)


The company I work for has had 2-way-radio-equipped vehicles for more than 30 years. I have one parked outside right now. In recent years they’ve hired a radio tech to install the radios in new vehicles or move them from one vehicle to another, but years ago we did it ourselves.

I don’t think I’d take power for a 2-way from a cigarette lighter circuit. We used to run a heavy wire (fused, of course) directly to the battery. Those radios draw a lot of current when broadcasting. You should be able to find a suitable ground connection somewhere in the interior. Make sure you turn the 2-way radio off when you park the car, because it will quickly drain the battery if it’s on.

Antenna installation was alway fun. Roof-top mounting required removal of much interior trim and drilling a 1" diameter whole in the roof. There are brackets for fender mounting which do not require drilling large holes, but you still have to run the antenna wire through the firewall or into the trunk cavity.

You’ll probably end up taking a lot of the interior apart now matter where you put the antenna. Your service manual will come in very handy for this.

Please be advised that talking on a 2-way while driving is a significant distraction, just like using a cell phone.

in addition to what mcparadise said, remember to consider your ground plane unless the antenna takes care of that for you, and don’t make the rookie mistake of mounting the antenna directly behind the sunroof. Your best bet would be (depending on what car you have) right in the middle of the trunk.

I worked for Motorola in Zurich Switzerland and did hundreds of 2 way and cell phone installs (not much difference with a cell phone install than a 2 way) you can pull power directly off a fused circuit you make from the battery (this is what I did almost 100% of the time) or from the inside of the car, no matter what all the theoretical people said it never mattered. When mounting the antenna try to think of the distant between the transmitter/reciever and the antenna will be from each other as this will set the degree of difficulty in running the cable. The idea about the battery acting as a sponge and cleaning up the DC is a great theory but it never made any difference in actuality. Just make sure you cut your antenna the right lenght and put the little tip on it and perhaps give the antenna a front to back check out if you have the correct meter (we did).

Working with Motorola in Switzerland I was called to do alot of installs on Fire and Police vehicles. I can remember the Fire people wanted every piece of comm. gear to turn on simply by turning one big switch (they said it was common to forget to turn the radio on if you got a call that woke you up) and I remember one install that I did for the Police that included a foot activated microphone switch for clandestine survailance (the car had a electric heater in it also). Being an American and working on these undercover type cop cars always made me chuckle as there was absolutely no background check. I worked at Kloten Airport(in Zurich) maintaining electricals on small jets and I daily passed through customs (the one reserved for high roller private jet type people) probably 6 times a day,was never searched, and again this was all without a background check. Boy people were sure trusting in the 80’s, but when the EL Al aircraft landed 3 little armoured cars would run out and follow the plane around. The Russian cargo jets were the absolute loudest and most polluting aircraft allowed to land,quite a sight. Perhaps I was “background” checked and just never knew it. I do like that I was able to take part a bit in the fall of the wall in 1989 (but I could not stay long in Berlin) but never managed to vist Normandy. As big a deal the wall comming down was in Germany the Swiss were very reserved about the entire matter.All this was possible as I was married to a Swiss girl at the time.