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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1772 (Heating, Ventilation And Air Conditioning) >> Diagnostic Information and Procedures >> Noise Diagnosis - HVAC Module

Noise Diagnosis - HVAC Module

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Noise Diagnosis - HVAC Module

Step Action Yes No
DEFINITION: Noise originating from the HVAC module.
1 Were you sent here from Symptoms or another diagnostic table? 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:
    • Blower motor speeds
    • HVAC modes
    • Temperature control settings
  3. Determine 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 6 
6
  1. Remove the instrument panel center trim bezel. Refer to Trim Bezel Replacement - Center in Instrument Panel, Gages and Console.
  2. Remove the center air outlet duct.
Is the action complete?
Go to Step 7  -
7
  1. Inspect the air flow doors for proper operation.
  2. Inspect the ducts for obstructions or foreign materials.
Were any of these conditions found?
Go to Step 10  Go to Step 8 
8 Inspect the mode and temperature doors and seals for warping or cracking.
Are the doors in normal condition?
Go to Step 11  Go to Step 9 
9 Replace the appropriate door and/or seals.
Is the repair complete?
Go to Step 11  -
10 Remove any obstructions or foreign material found.
Is the action complete?
Go to Step 11  -
11
  1. Install the center air outlet duct.
  2. Install the I/P center trim bezel. Refer to Trim Bezel Replacement - Center in Instrument Panel, Gages and Console.
Is the action complete?
Go to Step 12  -
12 Operate the system to verify the repair.
Did you find and correct the condition?
System OK Go to Step 2