Refrigerant System - Testing

DIAGNOSIS
To diagnose the Electronic Climate Control (ECC) System in the shortest time and with the least amount of effort, it is important to know how a properly functioning system will perform. For diagnosis of all ECC functions, refer to CLIMATE CONTROL DIAGNOSIS.

TESTING THE REFRIGERATION SYSTEM

If a malfunction in the refrigeration system is suspected, first check the diagnostic codes. Then check the following items:
1. Check outer surfaces of the radiator and condenser cores to be sure that airflow is not blocked by dirt, leaves or other foreign material. Be sure to check between the condenser and radiator as well as the outer surfaces. Clean as required.
2. Check for restrictions or kinks in the evaporator and condenser cores, hoses, tubes, etc... Replace as required.
3. Check for refrigerant leaks.
4. Check all air ducts for leaks or restrictions. Low airflow rate may indicate a restricted or frozen evaporator core. Repair as required.
5. Check for compressor clutch slippage. Check compressor clutch coil current (3 to 6 amps) or resistance (3 to 5 ohms) and compressor clutch operation. Repair or replace as necessary.
6. Check for improper serpentine drive belt tension or excessive wear. Replace as required.
7. Check for plugged accumulator or expansion tube. Replace as required.
8. Check cooling fan operation.