I had a D3 installed in a '06 Chevy but the screen it's too bright at night. The installer said because of the way some late model car and trucks are with day running lights it can't be done without modifications. Is he right or mis informed?

That would be a misinformed installer. You can always hook up the illuminatioin wire. It may unexpectedly switch the screen over to night mode with autoheadlights. But it can ALWAYS be hooked up.

He said it's because the dash lights are always on by default on my truck.

You just have to go somewhere else for the illumination feed is all. Normally in gms I'll either go to the parking light circuit or the headlight circuit and tap there.

Do you know a good place to tap the ILL on a Hummer H2?

Another member had suggested the wire for the roof running lights in the A-frame, but I was not able to clearly find one there. I have fully installed and ran the ILL wire (disconnected) to below the steering wheel where I can access it easily. I am hoping for a connection somewhere near the fusebox to the left of the dash with driver door open.

Any suggestions?

I used a wire on the back of the headlight light switch on my 2006 Silverado. I would search around on this forum. There is a post on this.....

I just ran mine to a switch then to an acc wire, and I can turn it on and off whenever I want. I too have headlights that are on all the time and the black background got kind of hard to see during the day so I changed it.

I leave my lights set on "Auto" and am looking to tap a source that comes on with the headlights and is NOT dimmed.

I had a dimmed source hooked up, and the D3 illumination was reverse with respect to the dimming function (interior light low & D3 bright vs. interior bright & D3 dark)

The Ill wire in the H2 is in the very top of the A-piller. Remove the handle from the piller and the trim will come off. Remove the one screw holding the far left marker lamp and it will come off. Pull on the wires where they run through the grommet under the light and the grommet will pop out of the hole. Tap into the wire(on the under side of the grommet) that goes 12V w/ lights on and run the wire down the A-piller to the AVIC. Make sure to put the grommet back into the hole or all the water that sits on the roof will end on the floor in the truck!

As an alternative, I would be willing to bet that if you look at the light switch on the hummer, you can find it there. I found it on my silverado by accident when I installed guages. I would think that most everything in your dash that is dimmed will work, you just have to find the right wire with a DVM

Thanks Shotgun.

I was looking for it in the A-pillar, and couldn't find it as a separate set of wires. By that point it was tightly bundled and packaged with other wires.

It makes sense to get it at the running light, I actually had that grommet out to see if I could back trace the wires!

Any way to tell which of the 2 wires is the "hot" one, without first splicing into it and testing?

On another note, I was able to run the BTB200 MIC wire through the A-pillar to the ceiling location of the Onstar MIC. The BTB200 MIC wire exits the ceiling at the edge of the Onstar MIC cutout, with the BTB200 MIC attached to the ceiling at that point. Excellent MIC position!

I think it's grey/black stripe. But, you should test w/ a multi-meter.

Any reccomendations where to hit the parking lights in a 06 trailblazer ss? There is no wire that goes to 12v with movement of the switch on the switchpanel.