System Performance Test - Temp & Pressure Relationships

Fig. 42 A/C system performance test (recirculation-to-discharge air temperature).:

Fig. 43 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. Temperature lever position must be in the maximum cold position and mode lever position must be in the vent position.
d. The intake lever position must be in the recirc position with the A/C switch in the on position and the fan lever in the hi 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. 42 & 43 for recirculating to discharge air temperature and ambient temperature to compressor pressure test readings.