GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

  1. Turn ignition switch to the Run position.
  2. Rotate the front blower switch through all fan speeds:
  3. • Low
    • Med 1
    • Med 2
    • High

The blower motor runs in all positions.

2

Turn the front blower switch to the Off position.

Blower motor stops running

Blower Motor Always On

3

Rotate the Auxiliary HVAC Control Module, Front through all fan speeds:

    • Low
    • Med
    • High
  1. Turn the Auxiliary HVAC Control Module, Front to the Rear position.
  2. Rotate the Auxiliary HVAC Control Module, Rear through all fan speeds:
  3. • Low
    • Med
    • High

The auxiliary blower motor runs in all positions.

4

Turn the Auxiliary HVAC switchs to the Off position.

Auxiliary blower motor stops running

Auxiliary Blower Motor Always On

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.