DEFINITION: Noise originating from the blower motor and/or the air delivery system. No loss of battery or ground is occurring in the blower motor circuit. The blower control module and the blower motor are not exhibiting any intermittent internal shorts. For Electrical diagnosis of the blower motor circuit, refer to Blower Motor Inoperative in HVAC Systems - Automatic.

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic in HVAC Systems - Automatic.

1. Sit inside the vehicle.
2. Close the vehicle doors and windows.
3. Turn the ignition ON with the engine OFF.
4. Set the blower to HIGH.
5. Set the temperature control to full cold.
6. Set the mode control so that the air comes out of the IP vents.
7. Cycle through all of the blower motor speeds, modes (including outside air and recirc), and temperature control positions to determine where and when the noise occurs.
8. Attempt to define the type of noise:

•	Scrape, pop

•	Tick/click, chirp, groan

•	Air rush, whistle

Is a scrape or pop noise evident when selecting modes or temperature settings (moving a mode or temperature valve)?

Go to Step 8

Go to Step 3

Is a tick/click, chirping, or groaning or scraping noise present - constantly, but decreases as blower motor speed is decreased, or only at startup/intermittent - in all modes?

Go to Step 6

Go to Step 4

Is an air rush/whistle noise evident at all blower speeds?

Go to Step 9

Go to Step 5

Is the complaint of an air rush/whistle noise only while the vehicle is moving?

Go to Step 12

Go to Step 9

1. Inspect the instrument panel, defroster, and heater ducts/vents for blockage or foreign material.
2. Remove and repair as necessary.

Did you find and correct the condition?

System OK

Go to Step 7

1. Remove the blower motor. Refer to Blower Motor Replacement .
2. Examine the blower motor, impeller, and the blower motor cavity for the following conditions:

•	Missing or damaged seal (blower motor to case)

•	Deposits of foreign material

•	Wear spots

•	Cracked blades

•	Cracked hub

•	Loose impeller retainer

•	Loose or missing impeller balance weights

•	Improper impeller alignment

•	Roughness while sinning the impeller

3. Remove the material and/or repair or replace the blower motor assembly.
4. Install the blower motor and impeller assembly. Refer to Blower Motor Replacement .

Did you complete the repair?

Go to Step 13

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1. Isolate the noise.
2. Inspect for a noisy actuator or binding valve door.
3. Repair as necessary.

Did you complete the repair?

Go to Step 13

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1. Inspect the instrument panel, defroster, and heater ducts/vents for blockage or foreign material.
2. Remove and repair as necessary.

Did you find and correct the condition?

System OK

Go to Step 10

1. Remove the blower motor. Refer to Blower Motor Replacement .
2. Examine the blower motor, impeller, and the blower motor cavity for the following conditions:

•	Missing or damaged seal (blower motor to case)

•	Deposits of foreign material

•	Wear spots

•	Cracked blades

•	Cracked hub

•	Loose impeller retainer

•	Loose or missing impeller balance weights

•	Improper impeller alignment

3. Remove the material and/or repair or replace the blower motor assembly.
4. Install the blower motor and impeller assembly. Refer to Blower Motor Replacement .
5. Operate the blower motor.

Is the noise still present?

Go to Step 11

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The noise may be caused by either a misaligned duct in the instrument panel, or a misaligned door or seal in the HVAC module.

1. Remove the IP assembly. Refer to Instrument Panel Assembly Replacement in Instrument Panel Gages and Console.
2. Inspect the ducts for proper alignment.
3. Inspect the valve door seals for looseness or misalignment.
4. Repair or replace as necessary.

Did you complete the repair?

Go to Step 13

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1. Inspect the base of the windshield and cowl area for leaks.
2. Inspect the seals around the HVAC case at the front of the IP.
3. Repair as necessary.

Did you complete the repair?

Go to Step 13

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Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2