For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
A constant air rush noise is typical of high speed blower operation. Some systems and modes may be worse than others. If possible inspect another similar vehicle (same model) in order to determine whether the noise is typical of the system as designed or excessive.
1 | Inspect the blower electrical connections and grounds. Refer to HVAC Blower Control Schematics . Is the repair complete? | -- | Go to Step 2 | --
2 |

1. Sit inside vehicle.
2. Close all door and windows.
3. Turn ignition switch to ON
4. Set the blower speed to HI.
5. Set the mode to VENT.
6. Set the temperature control to full COLD.
7. Cycle through all blower speeds, modes, and temperature control positions to determine where noise occurs and where it does not occur.

Is the blower making a constant whine, tick/click, flutter or scraping noise, but it lessens with a lower blower speed?

--

Go to Step 4

Go to Step 3

3 | Is the blower making a squeal/screech noise at start-up only and/or sometimes intermittent? | -- | Go to Step 4 | Go to Step 7
4 | Inspect for blower motor and fan vibration at each blower speed by feeling the blower case. Is the vibration excessive? | -- | Go to Step 6 | Go to Step 5
5 |

1. Remove the blower from the blower case. Refer toBlower Motor and Fan Replacement .
2. Inspect for foreign material at opening of blower intake.

Was foreign material found?

--

Go to Step 10

Go to Step 6

6 |

1. Inspect the blower fan for wear spots, cracked blades, or hub, loose fan retainer, and fan alignment.
2. Inspect the blower case for wear spots.

Was any wear found?

--

Go to Step 11

Go to Step 12

7 |

1. Set blower speed to HI.
2. Inspect full HOT to full COLD temperature positions in VENT, HEAT, and DEFROSTER modes.

Is the excessive blower noise in VENT mode only?

--

Go to Step 13

Go to Step 8

8 | Is the excessive blower noise in the HEAT and/or DEFROST modes only? | -- | Go to Step 14 | Go to Step 9
9 | Is excessive blower noise in all modes but not all temperature positions? | -- | Go to Step 15 | Go to Step 16
10 | Remove the foreign material from the blower assembly. Repair as necessary. Is the repair complete? | -- | Go to Step 17 | --
11 | Repair blower fan and/or blower case as necessary. Is the repair complete? | -- | Go to Step 17 | --
12 | Replace the blower motor and fan. Refer to Blower Motor and Fan Replacement . Is the repair complete? | -- | Go to Step 17 | --
13 |

1. Inspect the air ducts for obstructions and foreign material.
2. Inspect the vent door seals.
3. Repair as necessary.

Is the repair complete?

--

Go to Step 17

--

14 |

1. Inspect the air ducts for obstruction and foreign material
2. Inspect the heater and/or defroster door seals.
3. Repair as necessary.

Is the repair complete?

--

Go to Step 17

--

15 | Inspect the temperature door seals and repair as necessary. Is the repair complete? | -- | Go to Step 17 | --
16 | Inspect the heater system for obstruction or foreign material between the blower fan and the temperature door. Repair as necessary. Is the repair complete? | -- | Go to Step 17 | --
17 | Perform the functional test. Refer to Function Test . Is the repair complete? | -- | System OK | --