Verify the customer's complaint.

Are the customer's concerns verified?

Go to Step 2

System OK

1. Sit inside the vehicle.
2. Close the doors and the windows.
3. Turn the ignition ON.
4. Set the blower speed to 4.
5. Set the temperature to full cold.
6. Cycle through the blower speeds, the modes, and the temperature settings in order to find the noise.

Is the blower noise constant at high blower speeds or certain modes, but absent at lower speeds or in other modes?

Go to Step 11

Go to Step 3

Inspect for vibrations from the blower motor and fan assembly at each blower speed by feeling the blower motor housing.

Did you find excessive vibration?

Go to Step 6

Go to Step 4

1. Remove the blower motor and the fan assembly. Refer to Blower Motor Replacement .
2. Inspect for foreign material at the opening of the blower inlet.

Do you find any foreign material at the blower inlet?

Go to Step 5

Go to Step 6

Remove all foreign material.

Is the repair complete?

System OK

Go to Step 6

1. Examine the blower fan for wear spots, cracked blades, a cracked hub, a loose fan retaining nut, or bad alignment.
2. Examine the blower case for wear spots.

Did you find any problem?

Go to Step 7

Go to Step 9

Lubricate the motor.

Is the repair complete?

System OK

Go to Step 8

Replace the motor and the fan assembly.

Is the repair complete?

System OK

Go to Step 9

If the noise is a click, tick or whine, replace the motor.

Is the repair complete?

System OK

Go to Step 10

Reinstall the original motor.

Is the problem still present?

Go to Step 11

System OK

1. Set the blower speed on 4.
2. Inspect full-hot to full-cold temperature positions in the defrost, floor, and vent modes.

Is the noise present in the defrost mode only?

Go to Step 12

Go to Step 13

1. Inspect the ducts for obstructions or foreign materials.
2. Remove any obstructions or foreign materials.
3. Inspect the floor/defroster door seals.
4. Repair or replace the components, as needed.

Is the repair complete?

System OK

--

Is the noise present in the floor mode only?

Go to Step 12

Go to Step 14

Is the noise present in the vent mode only?

Go to Step 15

Go to Step 16

1. Inspect the ducts for obstructions or foreign materials.
2. Remove any obstructions or foreign materials.
3. Inspect the vent door seals.
4. Repair or replace the components, as needed.

Is the repair complete?

System OK

--

Is the noise present in all modes, but not all temperature positions?

Go to Step 17

Go to Step 18

1. Inspect the temperature door seals.
2. Repair or replace the seals, as needed.

Is the repair complete?

System OK

--

1. Inspect the system for obstructions or foreign materials between the fan and the temperature door.
2. Repair or replace the components, as needed.

Is the repair complete?

System OK

Go to Step 2