I've seen many questions on the illumination issues and have read them all. Unfortunately I was unable to find the answer I'm looking for. I just installed an AVIC-D3 in my 2007 Trailblazer (without Bose). I used a GMOS-01 harness which instructed me to hook up to the orange/white illumination wire on the Avic which I did and tested for continuity. However my illumination is always Off in the hardware info. I've read even though I have auto headlights this should still function properly.

 

Anyone with a Trailblazer and GMOS-01 harness have any luck with the Illumination? What could I check?

 

Thanks.

Apparantly the GMOS-01 is supposed to bring the illumination to the AVIC. Which it did because I hooked it up. But it's not working.

 

What are the Trailblazer owners doing?

You need to connect the orange/white from the D3 to the Parking Light wire in the main harness under the dash. It is Brown and you need to test because there are several brown wires in this harness. You are looking for the wire that shows 12 volts when the Parking Lights are turned on, and nothing when they are turned off. There is no need to turn on the ignition when you test, only the headlight switch.

 

Hope this helps.

Thanks Marc. Where exactly is this harness? Under the steering column?

 

Why would the GMOS-01 harness have me hook up the Orange/White avic wire if it's not even working... Strange.

Yes, it is under the column. It runs left to right in the dash, and should be taped up with only one layrt of tape. I have found the parking light wire to usually be buried in the center of the wires, and should be a 16 guage wire.

 

The GMOS-01 is supposed to have that output, but I have never seen it work. That's why I have gone to finding the parking light wire instead. Be glad you don't have an H2 Hummer as they have those wires under the hood.

try to dimm the light a little bit whit the dimmer and it should work...

On my car when the light is full power it's always day mode but when I dimm it a little bit, it's night mode... Like if the voltage was to high