GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 2004 🢒 Silhouette Ext. 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Noise Diagnosis - Auxiliary Blower Motor

Step

Action

Yes

No

DEFINITION: Noise originating from the auxiliary blower motor.

1

Were you sent here from Symptoms or another diagnostic table?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

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

Is a noise evident during auxiliary blower operation?

Go to Step 3

Go to Step 12

3

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

Is excess vibration present?

Go to Step 5

Go to Step 4

4

Listen to the auxiliary blower motor at each blower speed.

Is the auxiliary blower motor making a squeaking or chirping noise?

Go to Step 10

Go to Step 12

5

Inspect the blower motor and the blower motor housing for proper installation.

Is the blower motor or the blower motor housing touching the vehicles body and causing the vibration?

Go to Step 9

Go to Step 6

6
  1. Remove the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .
  2. Inspect the auxiliary blower motor impeller for deposits of foreign material.
  3. Inspect the auxiliary blower motor for deposits of foreign material.

Did you find foreign material on the auxiliary blower motor?

Go to Step 8

Go to Step 7

7

Inspect the auxiliary blower motor for the following conditions:

  1. Cracked blades
  2. A loose impeller retainer
  3. Improper impeller alignment

Did you find any of these conditions?

Go to Step 10

Go to Step 11

8

Remove the foreign material.

Is the action complete?

Go to Step 11

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9

Install the component so there is no contact with the vehicles body.

Is the action complete?

Go to Step 12

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10

Replace the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Is the repair complete?

Go to Step 12

--

11

Install the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Is the action complete?

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2