GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Astro - 4WD 🢒 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 10

3

Does the noise vary with the auxiliary blower speed?

Go to Step 4

Go to Step 5

4

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

Is excess vibration present?

Go to Step 5

Go to Step 10

5
  1. Remove the auxiliary blower motor. Refer to Noise Diagnosis - Blower Motor .
  2. Inspect the auxiliary blower motor for deposits of foreign material.

Did you find foreign material on the auxiliary blower motor?

Go to Step 7

Go to Step 6

6

Inspect the auxiliary blower motor for the following conditions:

    • Cracked blades
    • A loose impeller retainer
    • Improper impeller alignment

Did you find any of these conditions?

Go to Step 8

Go to Step 9

7

Remove the foreign material.

Is the action complete?

Go to Step 10

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8

Replace the auxiliary blower motor. Refer to Noise Diagnosis - Blower Motor .

Is the action complete?

Go to Step 10

--

9

Install the auxiliary blower motor. Refer to Noise Diagnosis - Blower Motor .

Is the action complete?

Go to Step 10

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10

Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2