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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 23 (HVAC Systems - Manual) >> Symptom Tests >> HVAC Module Noise Diagnosis

HVAC Module Noise Diagnosis

WARNING: This page is about a different car, the 2002 GMC Safari and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Definition: Noise originating from the HVAC module.
  1. Were you sent here from SYMPTOM DIAGNOSIS  or another diagnostic table? If so, go to next step. If not, see TROUBLE SHOOTING .
  2. Start the engine. Cycle through all of the following: Blower motor speeds, HVAC modes and temperature control settings. Determine the type of noise: Scrape, pop, tick/click, chirp, groaning or air rush/whistle. Is a scrape or pop noise evident when selecting modes or temperature settings? If so, go to step  6. If not, go to next step.
  3. Is a tick/click, chirping, groaning or scraping noise present, but decreases as blower motor speed is decreased? If so, go to step  6. If not, go to next step.
  4. Is an air rush/whistle noise evident in all modes but not all temperature settings? If so, go to step  6. If not, go to next step.
  5. Is an air rush/whistle noise evident only in defrost or floor mode? If so, go to next step.
  6. Remove the instrument panel carrier. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. Go to next step.
  7. Inspect the air flow doors for proper operation. Inspect the ducts for obstructions or foreign materials. Were any of these conditions found? If so, go to step  10. If not, go to next step.
  8. Inspect the mode and temperature doors and seals for warping or cracking. Are the doors in normal condition? If so, go to step  11. If doors are damaged, go to next step.
  9. Replace the appropriate door and/or seals. After repairs are complete, go to step  12.
  10. Remove any obstructions or foreign material found. After repairs are complete, go to step  11.
  11. Install the instrument panel carrier. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. After repairs, go to next step.
  12. Operate the system in order to verify the repair. If system operates normally, repair is complete. If system still malfunctions, return to step  2.
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