GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Sierra - 4WD 🢒 Power and Signal Distribution 🢒 Wiring Systems and Power Management 🢒 HVAC Schematics
Figure 1:

Module Power, Ground, Serial Data and Blower Controls
Object Number: 1844388 Size: FS
Master Electrical Component List
Air Delivery Description and Operation
Control Module References
Mode Controls
ECM-BATT, HDLP WASH, HVAC BATT, IPC, LTR, S/ROOF and TCM-BATT Fuses
ABS-1, ABS-2, HEAVY DUTY ABS, HVAC BLWR, STUD 1, STUD 2 and WSW/HTR Fuses
Low Speed Bus - 1 of 3
Ignition III Voltage and Accessory Voltage
G201 1 of 2
G200 1 of 2
Figure 2:

Mode Controls
Object Number: 1844389 Size: FS
Master Electrical Component List
Air Delivery Description and Operation
Control Module References
Temperature Controls
Module Power, Ground, Serial Data and Blower Controls
RUN/CRANK BUS - AUX HVAC- IGN and HVAC-IGN Fuses
Temperature Controls
Temperature Controls
Temperature Controls
G106 (4.3L) and G103
G102, G107 (4.3L), G104, G108
Figure 3:

Temperature Controls
Object Number: 1844390 Size: FS
Master Electrical Component List
Air Temperature Description and Operation
Control Module References
Temperature Sensors
Mode Controls
Mode Controls
Mode Controls
Mode Controls
Mode Controls
Headlight and Daytime Running Light Control
G201 1 of 2
Figure 4:

Temperature Sensors
Object Number: 1844391 Size: FS
Master Electrical Component List
Air Temperature Description and Operation
Control Module References
A/C Compressor Controls
Temperature Controls
G200 1 of 2
Figure 5:

A/C Compressor Controls
Object Number: 1844392 Size: FS
Master Electrical Component List
Air Temperature Description and Operation
Control Module References
Temperature Sensors
A/C CMPRSR, FRT WASH, FUEL PUMP, HORN, HTD MIR, REAR DEFOG and STRTR Fuses
Low Speed Bus - 1 of 3
G106 (4.3L) and G103
G106 (4.3L) and G103
G102, G107 (4.3L), G104, G108