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

Except Envoy


Object Number: 682302  Size: FS
Master Electrical Component List
Envoy Only
INT BATT Fuse
AUX PWR, RDO BATT and HDLP SW Fuses
Power, Ground, Transfer Case Shift Control Module and Vehicle InterfacE Unit (VIU)
G203 and G204 (Pickup)
Headlight Leveling Schematics (Export)
Audio Amplifier Power and Ground (Chevy/GMC)
Figure 2:

Envoy Only


Object Number: 682304  Size: FS
Master Electrical Component List
Except Envoy
INT BATT Fuse
AUX PWR, RDO BATT and HDLP SW Fuses
Power, Ground, Transfer Case Shift Control Module and Vehicle InterfacE Unit (VIU)
G203 and G204 (Envoy)
G204 and G205 (Envoy)
Automatic Level Control Schematics
G470 (Envoy)