A/C System Performance Test - HVAC System - Manual

System Performance Test (Part 1 Of 2):

System Performance Test (Part 2 Of 2):

Use this test and the accompanying chart in order to aide in the evaluation of the Air Conditioning (A/C) system performance. While increased engine RPM may provide extra capacity and cooler A/C discharge temperatures, the test results may not be repeatable due to other variables. The following test procedure must be followed.
1. Park the vehicle indoors or in a shaded area.
2. Engage the parking brake.
3. Open the hood, the doors, and the windows in order to ventilate the interior.
4. Vent the engine exhaust, if necessary.
5. Install the high and the low side pressure gauges.
6. Record the ambient temperature at the vehicle.
7. Record the temperature and the relative humidity by using a psychrometer or by consulting the local weather bureau.
8. Close the doors.
9. Close all of the windows.
10. Place the transmission in park (auto) or in neutral (manual).
11. Start the engine.
12. Set the mode control to the upper mode setting.
13. Depress the A/C and the Max/Recirculation buttons.
14. Set the blower speed to the HIGH position.
15. Set the temperature control to the FULL COLD position.
16. Open the A/C outlets.
17. Install a temperature tester into the left center A/C outlet.
18. Stabilize the engine speed to idle RPM.
19. Start the timer.
20. Operate the A/C system for about 5 minutes or until the left center outlet reaches the lowest temperature.
21. Record the following data:
- The left outlet air temperature
- The high-side pressure
- The low-side pressure
22. Turn the ignition off.
23. Compare the readings with the following table.
24. Normally operating A/C systems should be within 5 degrees and 10-20 PSIG of the levels appearing in the table.