Test Description

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

6. This step tests the output from the blower motor switch. Loss of blower motor switch output would indicate a malfunctioning switch or a circuit malfunction in the supply voltage to the switch.
7. There are two ignition 3 voltage circuits at the HVAC control module. Test the circuit that provides the supply voltage to the blower motor switch.

Fig 1: Blower Motor Inoperative (Steps 1-7)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Blower Motor Inoperative (Steps 8-16)

Courtesy of GENERAL MOTORS CORP.