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

LH Heated Seat


Object Number: 670105  Size: FS
Master Electrical Component List
Heated Seats Description and Operation
RH Heated Seat
HTD SEAT, ATC, HVAC and A/C Fuses
S313 and S419
G420,G450 and S427 (Utility w/ Endgate and Crew Cab)
B+ Bus Bar
Ign ACC, RUN and RAP Bus Bar
HVAC and CRUISE Fuses
HVAC and CRUISE Fuses
Figure 2:

RH Heated Seat


Object Number: 670107  Size: FS
Master Electrical Component List
Heated Seats Description and Operation
LH Heated Seat
B+ Bus Bar
HTD SEAT, ATC, HVAC and A/C Fuses
S320 and S420
G420,G450 and S427 (Utility w/ Endgate and Crew Cab)
Ign ACC, RUN and RAP Bus Bar
HVAC and CRUISE Fuses
HVAC and CRUISE Fuses