Honda GL-1500 Radio Interface

A discussion about the radio interface connector on the Honda GL-1500.

Install my 2-mtr radio on my 1990 GL-1500 in such a way as to keep it weather/theft protected, yet allow easy operation from my handlebars. Incorporate the up/down/ptt switches on my stock Honda CB to work with my 2-mtr radio keeping each operating independently of each other while simultaneously allowing audio input from both into existing stereo system on the motorcycle. Since I always wear a helmet I only cared about audio in/out in this mode. There is no reason you can’t replace the 2-mtr radio with any other transceiver or CD player, etc.

At a GWRRA meeting I attended, I was introduced to Robert Chamberland who had done a similar setup on his bike. Bob had taken the time and figured out the pin-out of the stock CB connector, and his documentation makes it all possible. A friend of mine Gary Robin, K9HDU helped with the schematics.

On the left handlebar there is a cover, and under this cover the up/down/ptt wires can be accessed. Green & white wires are the PTT and Grn-Orn-Gry are the channel up/down wires. I extended these wires to the right (locked) faring pocket, installing a switch to change between the two radios. I then soldered two pieces of tiny coax to the harness connecting the CB radio to the stereo on the bike. One piece to pins 7 and 15, then went to the mike input on my 2 mtr radio. The other from pins 5 and 14 went to the external speaker jack of my 2-mtr radio. Be careful of the harness. It’s about $50 if you screw up. Mounting my ICOM 229A in a custom plastic mounting bracket in the faring pocket, I was then able to relock the cover. At the same time I mounted the switch next to the radio on the same mounting plate. Out of sight, out of mind and sort of weather proof.

That’s all there is to it, and best of all it works!

If you want to have the audio come over your stock speakers instead of the helmet connect a wire to pin 12. When grounded your bike speakers are active. When open your helmet speakers are active.

CB Wire Harness Pins
1. Ignition Switched Grn/Blk 12 Volt
2 Grounds When Active Org Ch Up
3 Grounds When Active Wht Tx (PTT)
4 Unknown
5 .1 ohm Audio Ground Pnk GND
6 Input to Speakers Blk Speaker
7 Output From Mike Red/Blu Mike
8 NC
9 Constant Red/Yel 12 Volt
10 Grounds When Active Gry Ch Down
11 TX Up/Dn Ground DGrn/Blk GND
12 Ground Spkr/Open Headset Brn Spkr/Headset
13 Unknown
14 Input to Headset Wht/Blk Headset
15 .1 ohm Mike Ground Blk GND
16 12 V Starter/Float When Running Yel/Red 12 Volt

Pins 5 and 14 used together connect to external speaker of 2-mtr radio (audio Out 2-mtr.)

Pins 7 and 15 used together connect to mike input of 2-mtr (audio IN 2-mtr.)

If you don’t have a factory CB installed, you can buy from Radio Shack their “Honda Accord Stereo Connector”, P/N 12-1379. Cut out one pit and mate directly with the stock CB/radio harness.

GL1500 radio interface diagram

2 thoughts on “Honda GL-1500 Radio Interface”

  1. Thanks for posting this information. I too own an 1990 1500 GL. I’m not sure where you installed the 2m radio? Did you put in place of the factory CB? It sounds like you might have left the CB where it was so I’m not sure what pocket you’re talking about? Are you talking about the pocket on the right that just has the locking lid that has two notches for where a hinge would be? Thanks again, Steve Wolfe, AI6ZW.


    1. In the article he mentions his ability to lock the cover. I think he is talking about the locking compartment.


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