I currently can get the head unit to turn on partially. The head unit glows but is not functional. In order to get it to fully work, I have to hit the CD eject button. This is what I have found as far as the wire colors go.

The 12v constant is Red/White.
The PWM + (the 12v switch) is yellow.
The PWM - is green.
Both the GM LAN1 and GM LAN2 are green.
The Antenna is Brown/White.

When I tested both green GM LAN wires, the light on the voltmeter was very dim and flickered very quickly.
The green PWM - also seems to be tied to the dimmer.

If anyone has any advice on how to get the head unit fully functional it would be much appreciated,
Nich