System Performance Test - Temp & Pressure Relationships

Fig. 48 A/C system performance test (recirculating-to-discharge air temperature).:

Fig. 49 A/C system performance test (ambient air temperature-to-compressor pressure).:

1. The system performance test must be performed as follows:
a. Vehicle must be parked indoors or in the shade and in a well ventilated place.
b. Vehicle doors must be closed with door windows and hood open.
c. Air control lever must be in vent-A/C position and temperature control lever must be in max cold position.
d. Air intake lever must be in recirc position and the fan control lever must be in No. 3 position.
e. Engine speed at 1500 RPM.
2. The time required before testing the system after the air conditioner starts operating should exceed 10 minutes.
3. Refer to Figs. 48 & 49 for suction to discharge air temperature and ambient air temperature to compressor pressure test readings. Measure discharge air temperature at center outlet grille, inside air relative humidity and temperature at blower assembly inlet and the ambient air relative humidity and temperature at a point 3.3 feet in front of condenser.