For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Were you sent here from the HVAC Symptoms? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual
2 |

1. Start the engine.
2. Cycle through all of the following settings:

• | Blower motor speeds

• | HVAC Modes

• | Temperature control settings

3. Attempt to define the type of noise:

• | Scrape, pop

• | Tick/click, chirp or groaning

• | Air rush/whistle

Is a scrape or pop noise evident when selecting modes or temperature settings?

Go to Step 6

Go to Step 3

3 | Is a tick/click, chirping, groaning or scraping noise present, but decreases as blower motor speed is decreased? | Go to Step 6 | Go to Step 4
4 | Is an air rush/whistle noise evident in all modes but not all temperature settings? | Go to Step 6 | Go to Step 5
5 | Is an air rush/whistle noise evident only in defrost or floor mode? | Go to Step 6 | Go to Step 7
6 | Remove the IP carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages and Console. Is the action complete? | Go to Step 7 | --
7 |

1. Inspect the air flow doors for proper operation.
2. Inspect the condition of the air flow doors.
3. Inspect the ducts for obstructions or foreign materials.
4. Inspect the temperature door seals.

Were any of these conditions found?

Go to Step 13

Go to Step 8

8 | Inspect the mode and temperature doors for warping or cracking. Are the doors in normal condition? | Go to Step 9 | Go to Step 11
9 | Inspect the HVAC ducts for any obstructions or foreign material. Were any obstructions found? | Go to Step 13 | Go to Step 10
10 | Inspect the temperature doors seals. Are the door seals in good condition? | Go to Step 14 | Go to Step 11
11 | Replace the appropriate door seals. Is the repair complete? | Go to Step 14 | --
12 | Replace the appropriate door. Is the repair complete? | Go to Step 14 | --
13 | Remove any obstructions or foreign material found. Is the action complete? | Go to Step 14 | --
14 | Install the IP carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages and Console. Is the action complete? | Go to Step 15 | --
15 | Operate the system to verify the repair. Is the system OK? | System OK | Go to Step 2