GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

DEFINITION: Noise originating from the blower motor.

1

Were you sent here from Symptoms or another diagnostic table?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic

2

Inspect the air inlet grille for debris.

Is debris present?

Go to Step 8

Go to Step 3

3

  1. Sit inside the vehicle.
  2. Close the vehicle doors and windows.
  3. Turn ON the ignition, with the engine OFF.
  4. Cycle the blower motor through all of the speeds in order to determine where and when the noise occurs.

Did you hear a noise during the blower operation?

Go to Step 4

Go to Step 11

4

Inspect for excessive vibration at each blower motor speed by feeling the blower case.

Is excess vibration present?

Go to Step 6

Go to Step 5

5

Listen to the blower motor at each blower speed.

Is the blower motor making a squeaking or chirping noise?

Go to Step 9

Go to Step 11

6

Important: Inspect the blower motor impeller cavity through the access hole in the air inlet grille.

Examine the blower motor cavity, blower motor and blower motor impeller for deposits of foreign material.

Did you find foreign material?

Go to Step 8

Go to Step 7

7

  1. Remove the blower motor. Refer to Blower Motor Replacement .
  2. Inspect the blower motor for the following conditions:
  3. • Cracked blades
    • A loose impeller retainer
    • Improper impeller alignment

Did you find any of these conditions?

Go to Step 9

Go to Step 10

8

Remove the foreign material.

Is the action complete?

Go to Step 11

--

9

Replace the blower motor. Refer to Blower Motor Replacement .

Is the repair complete?

Go to Step 11

--

10

Install the blower motor. Refer to Blower Motor Replacement .

Is the action complete?

Go to Step 11

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11

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2