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

Lumbar w/o Memory Seats


Object Number: 755941  Size: FS
Master Electrical Component List
Lumbar Support Description and Operation
Lumbar w/Memory Seats
POWER SEATS, POWER WINDOW Circuit Breakers and RAP Relay
POWER SEATS, POWER WINDOW Circuit Breakers and RAP Relay
S313 and S419
G420, G450 and S427 - Utility and Crew Cab
B+ Bus Bar
S320 and S420
Figure 2:

Lumbar w/ Memory Seats


Object Number: 755942  Size: FS
Master Electrical Component List
Lumbar Support Description and Operation
Lumbar w/o Memory Seats
B+ Bus Bar
HTD SEAT, ATC, HVAC and A/C Fuses
S313 and S419
G420, G450 and S427 - Utility and Crew Cab
HTD SEAT, ATC, HVAC and A/C Fuses
S320 and S420