Symptom Diagnostic Charts

Use the following "Hand-Feel" procedure to quickly determine whether or not the A/C system has the proper charge of Refrigerant-12 (providing ambient air temperature is above 21°C (70°F). This check can be made in a matter of minutes, simplifying system diagnosis by pinpointing the problem to the amount of the R-12 charge in the system or by eliminating a low charge possibility from the overall checkout.

1. Engine must be warm and at normal idle speed.

2. Hood and body doors open.

3. Selector (mode) lever set at "NORM."

4. Temperature lever at "COLD"

5. Blower on "HI"

6. "Hand-Feel" the temperature of the evaporator inlet pipe after the orifice, and accumulator surface, with the compressor engaged.

- BOTH THE SAME TEMPERATURE AND SOME DEGREE COOLER THAN AMBIENT: A sufficient charge exists. Check for other problems. Refer to "Inspection of the Refrigerant System" in this section.

- IF TEMPERATURES VARY: Charge is insufficient. Leak test and check for other problems.

- Leak test. If leak found, discharge and repair as required. Evacuate and charge.


DELAYED A/C COOLING AFTER ENGINE START UP
Due to its variable displacement feature, special caution is necessary when diagnosing insufficient cooling conditions with the V-5 compressor. It is normal for liquid refrigerant to collect in the compressor crankcase during extended periods of shutdown, therefore, cooling action may be delayed up to 2 minutes until the refrigerant is pumped from the crankcase.

If you experience a delay in cooling upon start-up beyond 2 minutes, and the normal A/C compressor clutch diagnosis has been completed, follow the procedure outlined below:

1. Operate the A/C system by setting to "NORM" A/C mode and high blower.

2. Be sure the compressor clutch has engaged.

3. Idle the engine for 2 minutes with the A/C system operating.

4. If no cooling, run the engine at approximately 3000 RPM for 1 minute with the A/C system operating.

5. If no cooling, change the mode control to "VENT" position for 1 minute at idle.

6. Set A/C System back to "NORM" A/C mode, then run the engine at approximately 3000 RPM for 1 minute with the A/C system operating.

7. If no cooling, drive the vehicle in a normal manner for 5 minutes with the A/C operating.

8. If there Is still no cooling, perform the procedures outlined in the VDOT System Diagnostic Charts. Symptom Diagnostic Charts