GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

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

1

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

2

  1. Start the engine.
  2. Place the blower motor switch in the OFF position.

Is the blower motor OFF?

Go to Step 3

Go to Blower Motor Always On

3

Place the blower motor switch in each speed position.

Does the blower motor operate in any of the speed positions?

Go to Step 4

Go to Blower Motor Inoperative

4

Place the blower motor switch in each speed position.

Does the blower motor operate at the desired speeds?

Go to Step 5

Go to Blower Motor Malfunction

5

  1. Place the blower motor switch in the maximum speed position.
  2. Place the mode switch in the MAX position.

Does the recirculation door move to the recirculation position?

Go to Step 6

Go to Vacuum Control System Diagnostic

6

Place the mode switch in each mode position.

Does the air flow from the proper air distribution outlets in each mode position?

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

Go to Vacuum Control System Diagnostic