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

Headlamp Switch and Ambient Light Sensor


Object Number: 661617  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
Headlamp Dimmer, Park Gear Input, and High Beam Indicator
Left Underhood Fuse Block- RUN/CRK Fuse and IGN Relay
Battery Feed to Left and Right Underhood Fuse Blocks
Left Underhood Fuse Block- PCM, ABS, HZDT/SG, F/PMP, PK LP Fuses and F/PMP Relay
Battery Feed to Left and Right Underhood Fuse Blocks
Left Underhood Fuse Block- OXY SEN and SBM LCM Fuses
G202 (1 of 4)
G202 (4 of 4)
G202 (1 of 4)
G202 (2 of 4)
Figure 2:

Headlamp Dimmer, Park Gear Input, and High Beam Indicator


Object Number: 661618  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
Low Beam Headlamps
Headlamp Switch and Ambient Light Sensor
Auto Trans Shift Lock Control
G202 (4 of 4)
Figure 3:

Low Beam Headlamps


Object Number: 661619  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
High Beam Headlamps and Daytime Running Lamps (DRL)
Headlamp Dimmer, Park Gear Input, and High Beam Indicator
G104 and G106
G104 and G106
G105
G105
Figure 4:

High Beam Headlamps and Daytime Running Lamps (DRL)


Object Number: 661621  Size: FS
Master Electrical Component List
Exterior Lighting Systems Description and Operation
Low Beam Headlamps
G104 and G106
G104 and G106