GM Service Manual Online
For 1990-2009 cars only

If you suspect a problem in the refrigerant system, check for the following conditions.

  1. Check the outer surfaces of the radiator and the condenser cores to be sure that the airflow is not blocked by dirt, leaves, or other foreign material. Check between the condenser and the radiator, as well as all outer surfaces.
  2. Check for restrictions or kinks in the condenser core, the hoses, and the tubes.
  3. Check the operation of the blower fan.
  4. Check all the air ducts for leaks or restrictions. Low airflow rate may indicate a restricted evaporator core.
  5. Check for slippage of the compressor clutch.
  6. Check the drive belt tension.

Insufficient Cooling Quick Check Procedure

Perform the following hand-feel procedure to get a quick idea of whether the A/C system has the proper charge of refrigerant-134a. The air temperature must be above 21°C (70°F) for most models.

  1. Warm up the engine. Run the engine at idle.
  2. Open the hood and all the doors.
  3. Turn the A/C switch ON.
  4. Set the temperature control to the full cold position.
  5. Set the blower speed switch on the maximum speed setting.
  6. Hand-feel the temperature of the evaporator outlet pipe. The pipe should be cold.
  7. Check for other problems. Refer to HVAC Preliminary Checks .
  8. Leak check the system. Refer to Leak Testing . If you find a leak, discharge the system and repair the leak as required. After completing the repair, evacuate the system and charge it.
  9. If there is no leak, refer to Too Hot in Vehicle .