GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Power, Ground, Serial Data, Antenna and Front Speaker Outputs


Object Number: 2151411  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Control Module References
Center and Rear Speakers
B+ Bus 2 of 2
Fuse Block - Underhood F35 and F16 Fuses
GM Mid Speed Serial Data (CAN B)
G201 and G202
Figure 2:

Center and Rear Speakers


Object Number: 2151414  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Control Module References
Mobile Radio Provision and OnStar References
Power, Ground, Serial Data, Antenna and Front Speakers
Figure 3:

Auxiliary Input Provision and OnStar References


Object Number: 2151415  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Control Module References
Center and Rear Speakers
Vehicle Communication and Interface Module (VCIM) - Left