Functional Test

CCOT A/C System:

PSI Temp Relationship Of R12:

Humidity, Temp And PSI Relationship Of R12:

REFRIGERANT CHARGE QUICK-CHECK

^ Ambient Air temperature must be above 21°C (70°F).

1. Engine at normal operating temperature.

2. A/C "ON" and compressor running.

3. Temperature to coolest setting.

4. Blower on "HIGH."

5. Hand feel temperature of evaporator inlet pipe after expansion tube and accumulator surface.

a. Both same temperature and both some degree cooler than ambient = okay. If okay, check for other problems, Refer to Insufficient Cooling Diagnosis. Symptom Related Diagnostic Procedures

b. Inlet pipe cooler than accumulator surface = low refrigerant charge.

^ Recover A/C refrigerant, evacuate and recharge A/C system, Refer to Refrigerant Recovery and Recycling, Evacuating and Charging. Service and Repair

NOTE: If a malfunction in the refrigerant system is suspected due to abnormal system pressures, continue with Functional Inspection.

FUNCTIONAL INSPECTION

6. Check outer surfaces of radiator and condenser cores to be sure air flow 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.

7. Restrictions or kinks in evaporator core or condenser core, hoses, tubes, etc.

8. Refrigerant leaks.

9. Check all air ducts for leaks or restrictions. Low air flow rate may indicate a restricted evaporator core.

10. Compressor clutch slippage.

11. Drive belt tension.

12. Plugged accumulator or expansion (orifice) tube.

13. Excessive moisture in refrigerant system.

NOTE: For further system tests, Refer to Insufficient Cooling Diagnosis. Symptom Related Diagnostic Procedures