GM Service Manual Online
For 1990-2009 cars only

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This step tests for a blower motor that does not operate regardless of the desired blower motor speed.

  2. This step tests for a blower motor that operates, yet does not accurately respond to the desired blower motor speed.

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

DEFINITION: Air does not flow correctly from the air distribution outlets.

1

Did you review the HVAC operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

2

  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower control in the OFF position.

Is the blower motor OFF?

Go to Step 3

Go to Blower Motor Always On

3

Place the blower control in each speed position.

Does the blower motor operate at all?

Go to Step 4

Go to Blower Motor Inoperative

4

Does the blower motor operate correctly for each speed position?

Go to Step 5

Go to Blower Motor Malfunction

5

Is the HVAC control assembly mode selection inoperative in all positions?

Vacuum Control System Diagnostic

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems