i have a 2005 3.5l colorado and i am having problems with the ac and blower motor. if i pull out the hvac and test it with a test light, i have no ground working. so if i ground it out manually the blower works just fine. so i need help to find out where that ground point is. the other issue with the ac is it keeps blowing fuses. it is fine until i start the car but just leaving the key on doesnt hurt anything. i hooked up a test light to the fuse box. it grounds out one side when i start the car. please help.

The main ground fore the HVAC is under the hood behind the air filter. The wire grounds to the fender area, then is runs through a splice pack to ground various loads. The ground is g106, and the splice pack is sp106 in the diagram below.

From there, the wire goes inside the truck to a connector in the passenger side kick panel. Is is a 22 pin light gray connector and is labelled as c201 in the diagram.

The fuse issue is probably caused by the poor ground, so I would fix that first and see if the problem with the fuse goes away.




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(1)
Accessory Switch C2

(2)
Hazard Switch

(3)
Accessory Switch C1

(4)
Digital Radio Receiver (U2K)

(5)
Inflatable Restraint I/P Module

(6)
Ambient Light Sensor

(7)
Vehicle Communication Interface Module (VCIM) (UE1)

(8)
Courtesy Lamp - Footwell Right

(9)
Body Control Module (BCM) C2

(10)
C201 (I/P Harness to Body Harness)

(11)
HVAC Control Module C1

(12)
Auxiliary Power Outlet 2

(13)
Auxiliary Power Outlet 1

(14)
HVAC Control Module C2

(15)
Courtesy Lamp - Footwell Left

(16)
Data Link Connector (DLC)

(17)
C204 (Steering Column Harness to I/P Harness)

(18)
C208 (I/P Harness to Body Harness)

(19)
C200 (I/P Harness to Body Harness)

(20)
Headlamp and Panel Dimmer Switch

(21)
Instrument Panel Cluster (IPC)

(22)
Radio C1

(23)
Radio C2





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(1)
Wheel Speed Sensor (WSS) - LF

(2)
Brake Fluid Level Switch

(3)
Windshield Wiper Motor

(4)
Pass-through Grommet

(5)
Electronic Brake Control Module (EBCM)

(6)
Splice Pack SP105/G105

(7)
C102 (Body Harness to Chassis Harness)

(8)
C105 (4WD) or C106 (2WD) (Engine Harness to Body Harness)

(9)
Fuse Block - Underhood C4

(10)
Fuse Block - Underhood C5

(11)
Fuse Block - Underhood C7

(12)
Fuse Block - Underhood C6

(13)
C104 (Forward Lamp Harness to Body Harness) and C103 (Forward Lamp Harness to Body Harness)

(14)
Splice Pack SP106/G106

(15)
Wheel Speed Sensor (WSS) - RF

(16)
Powertrain Control Module (PCM) C1

(17)
Windshield Washer Fluid Pump

(18)
Pass-through Grommet

(19)
A/C Refrigerant Pressure Sensor