System Performance Test

Tool Required:
J 21213-A Four Jack-Dual Range Temperature Tester or Equivalent

1. Park the vehicle inside or in a shaded area.
2. Open hood, doors and windows to ventilate the interior.
3. Vent the engine exhaust, if necessary.
4. Open the hood and install high and low side pressure gages. Route lines over the front of the grille.
5. Close the hood completely.
6. Record the ambient temperature near the vehicle.
7. Record the temperature and relative humidity. Use a psychrometer or consult the local weather bureau.
8. Close all of the doors and leave the drivers and passengers windows open.
9. Set the mode control to "A/C," blower control on "HIGH," and temperature control on "Full Cold."
10. Open the air conditioning outlets.
11. Install J 21213-A or equivalent into the center air conditioning outlet.
12. Place the transmission in "PARK."
13. Start the engine, stabilize engine speed at 15000 RPM, and start the timer.
14. Run the air conditioning system for 10 minutes.
15. Record the outlet air temperature and high-side and low-side pressures.
16. Turn the engine off and compare the readings to the "A/C Performance Chart". Normally operating air conditioning systems should come close to the levels shown in the chart.




A/C PERFORMANCE CHART

If a malfunction is suspected due to abnormal system pressures, inspect the following:
1. Outer surfaces of radiator and condenser cores to make sure airflow is not blocked by dirt, leaves, or other foreign material. Make sure to check between the condenser and radiator as well as the outer surfaces.
2. Evaporator core, condenser core, hoses, tubes, etc., for restrictions or kinks.
3. Refrigerant leaks.
4. Air ducts for leaks or restrictions. A low airflow rate may indicate a restricted evaporator core.
5. Compressor clutch for slippage.
6. Drive belt for improper tension.
7. Accumulator for plugging.
8. Expansion (orifice) tube for plugging.

If the problem is not found, continue with the diagnostic procedures.