Newbie here, I just got the D3 and I am going to install it pretty soon. My question is, where do I find the VSS, PARKING BRAKE, AND BACKUP wires on an 04' GMC ENVOY w/o bose, onstar, and nav? Thanks in advanced.

Reverse Light lt. green + fuse box under left rear seat

Parking Brake lt. blue - switch or BCM, blk plug, pin A4

The BCM is attached to the fuse box under the left rear seat.

Speed Sense dk. green/white PCM

4.2L: The PCM is attached to the driver side of the engine. VSS is in the blue plug, pin 32.

5.3L: The PCM is near the lower front driver side of the engine. VSS is in the green plug, pin 50.

Thanks for your help. Now I can hook up my Radio!