Diagram for Gauge Cluster Connector

[J GTP]

I need a diagram showing the pinout for the black connector on the back of the gauge cluster in the picture below.

I bought an overlay for the cluster that needs 12v power and ground. I've hunted through the GM service manual, but I can't find anything. They only sent me instructions for other vehicles.

Maybe there's somewhere else I can splice into. I just figured it would need to be connected to the cluster harness in order for the dash lights to come on automatically at night.

 

[J GTP]

I dug out the multimeter and checked all of the wires myself. The black that you can see on top in the photo is the ground (second from the right)(pin Q). There are 2 reds on the bottom that both give constant 12v. I spliced into the visible one (pin D).

It works now, but the overlay has power whether the headlights are on or not. If I want it off, I have to use the switch that came with it. No big deal.

I checked for a wire that switches to 12v when the lights are on and there is one (light brown with black stripe)(pin E). I tried using it for the overlay power, but it didn't work. Not sure why.

 

[J GTP]

For anyone interested, here's some pics.

The first is the "white" setting which has a yellow tinge. The second is the "blue" setting which doesn't look blue to me at all. Looks like plain white. It's a bit brighter too. Lastly, no lights on.