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

Power, Ground, and DLC


Object Number: 1473365  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Speakers
B+ Bus - Underhood Fuse Block
Digital Radio - U2K
Data Link Connector (DLC) Schematics
OnStar Schematics
G300, G301, G302, and G303
Figure 2:

Speakers


Object Number: 1473366  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Digital Radio - U2K
Power, Ground, and DLC
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Figure 3:

Digital Radio - U2K


Object Number: 1473384  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Speakers
Power, Ground, and DLC
Data Link Connector (DLC) Schematics
Entertainment Schematic Icons
G300, G301, G302, and G303