GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)

1

  1. Place the ignition switch in the ON position.
  2. Place the blower motor speed selector in the OFF position.

The blower motor is off.

Blower Motor Always On

2

  1. Increase the blower speed to the highest speed .
  2. Decrease the blower speed until the blower speed is in the slowest speed.

The blower motor increases to maximum speed and then decreases to minimum speed.

Blower Motor Inoperative at Any Speed

3

  1. Place the ignition switch in the ON position.
  2. Place the mode selector in the AUTO mode.

The system switches to auto mode where the blower speed is controlled by the heater A/C control

Blower Motor Inoperative at Any Speed