Test Description

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 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.

2) - This step will determine if one or more blower speeds are inoperative.
4) - This step verifies if the HVAC control switch is attempting to control the blower motor speed.
5) - This step tests for a voltage change in the blower motor control circuit.

Fig 1: Blower Motor Malfunction Diagnosis (Steps 1-7)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Blower Motor Malfunction Diagnosis (Steps 8-12)

Courtesy of GENERAL MOTORS CORP.