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

Radio


Object Number: 1816875  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Speakers
CHMSL, PWR POST, and RDO/CHIME Fuses/Circuit Breakers
CHMSL, PWR POST, and RDO/CHIME Fuses/Circuit Breakers
Interior Lights Dimming Schematics
G119 and G120
Splice Pack SP203
Figure 2:

Speakers


Object Number: 1494119  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Radio