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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 >> HVAC Preliminary Checks

HVAC Preliminary Checks

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.

Most A/C system problems can be detected by a thorough visual and physical inspection of the system.

    IMPORTANT: The importance of this inspection cannot be stressed enough because proper heating and cooling depends upon adequate front air flow.
  1. Inspect air deflector, A/C condenser splash shield, condenser to radiator seal, and rear hood seal for missing or damaged parts.
  2. Inspect outer surfaces of radiator and condenser cores, to be sure air flow is not blocked by dirt, leaves, or other foreign material.
  3. Inspect for kinks in hoses and lines. Also inspect for refrigerant leaks using a blacklight or an electronic leak detector.
  4. Inspect for worn/loose drive belt or malfunctioning belt tensioner.
  5. Inspect blower motor operation at all speeds.
  6. With blower on high, inspect for equal distribution of air from all outlets.
  7. Inspect operation of mode control knob and distribution of air from designated outlets.
  8. Press recirc button with blower on high. A noticeable increase in air flow and sound should occur. Indicator should light.
  9. Start engine and run until it is up to operating temperature.
  10. Inspect operation of temperature control knob and air outlet temperature from hot to cold.
  11. Fig 1: Identifying Air Conditioning Compressor Pulley
    GM892736Courtesy of GENERAL MOTORS CORP.
  12. Press A/C button. Indicator should light. Inspect compressor for clutch engagement, slippage, or noise.
  13. Inspect electric cooling fan operation and speed as determined by system temperature and pressure.
  14. Turn OFF A/C. Compressor clutch should disengage.
  15. If any problem is found in any of the previous steps, go to the complaint condition cause charts.