So I installed my D3 about 2 weeks ago.It replaced the D1.Having a issue with the illumination wont darken when I turn my light one.The ill wires are connected.This is like the 400th radio I have put in.Never a problem.

Oh the car is a 07 Trailblazer SS.

dont know what wire it is on an 07, but make sure the one your using goes from ground to 12 volts when lights go on

yeah, or if you can find it, install a switch so that you can manually control it.

You know what, I just installed mine yesterday and haven't had a chance to play with it too much. but I noticed that in one of the menu areas, you can control the dimmer (dark to bright). I'll play with it when I get home and see if that is it. In the mean time, try that route. Let me know if it works.

So I installed my D3 about 2 weeks ago.It replaced the D1.Having a issue with the illumination wont darken when I turn my light one.The ill wires are connected.This is like the 400th radio I have put in.Never a problem.

 

Oh the car is a 07 Trailblazer SS.

The bold part is the reason your illumination isn't working.

I'm still trying to figure this out in my C6 as well. From what I've seen so far, it looks like there is no illumination wire in the radio harness, it's all controlled by the GM data bus. The bus sends a message to dim, and it's up to each individual device to adjust. Since the data bus doesn't connect to the AVIC, and the Peripheral adapter that I'm using doesn't handle this, it doesn't work. I think we will have to find a tap into the actual light circuit (at the bulb harness) to make it work.

^^^That up there would be a correct assumption.

Got mine working by tapping into one of the tail light harnesses yesterday. Not the quickest solution, but it works great.