Air Conditioning (A/C) System Performance Test

Air Conditioning (A/C) System Performance Test

Important:
* Before carrying out the high/low pressure and centre vent temperature testing, make sure that the vehicles A/C system has no visual or operational defects and that all refrigerant recovery and recharging safety requirements are adhered to. Refer to Refrigerant Recovery and Recharging (Refrigerant Recovery and Recharging) .

* Before commencing the testing follow the vehicle set up procedure. Failure to correctly set the vehicle up for testing will provide inaccurate diagnosis when comparing actual pressure readings to the table below.








1. Connect the calibrated high/low pressure gauges to the A/C system (1).

Important: Both high and low pressures should be within 50kPa of each other, if not a blockage may be present in the system.


2. Confirm that the static pressures (vehicle not started or A/C engaged) are correct.

Important: When possible the vehicle should be tested in direct sunlight, especially in the case of climate control vehicles using solar sensors.


3. Record the ambient temperature conditions and the relative humidity at the time of the test.
4. DO NOT test the vehicle with the condenser air flow restricted, such as against a wall.




5. Set the blower motor speed control (1) to the highest blower motor speed.
6. Set the temperature control (2) to the maximum cold setting.
7. Set the air intake mode control (3) to fresh air intake mode.




8. Set the mode outlet control to the face position with the instrument panel louvres open and facing straight ahead.

Important: Make sure that the thermometer probe is inserted to a length of approximately 50mm.


9. Insert a thermometer centrally into the face vent.
10. Turn the engine ON and run at idle speed.
11. Close all vehicle doors and windows.
12. Close the vehicle engine hood.

Important: For Accurate testing the relative humidity percentage (RH%) should be known, as you will see the pressures and vent temperatures alter as RH% changes. Refer to the A/C performance table below.


13. Make sure accurate pressure gauges are connected to the A/C system.
14. Turn the engine OFF and compare the readings with the data in the A/C performance table. A normally operating A/C system should not exceed levels shown. If the readings exceed the table limits, refer to Symptoms - HVAC Systems - Manual (Symptom Related Diagnostic Procedures) .