A/C Performance Testing

Air temperature in test room must be 70°F minimum for this test.
1. Connect tachometer and manifold gauge set to vehicle.
2. Set control to MAX A/C, temperature lever on full cool and blower on High.
3. Start engine and adjust to idle to 1000 RPM with A/C clutch engaged. Engine should be at normal operating temperature. Doors and windows should be closed.
4. Insert thermometer in left center A/C outlet and operate the engine for five minutes. The A/C clutch may cycle depending on ambient conditions.

Fig. 1 Performance Temperature Chart:

5. With A/C clutch engaged, compare discharge air temperature to A/C performance temperature chart.
6. Operate A/C for two minutes and take discharge air temperature readings.If temperature increased by more than 5°F, check blend air door for correct operation. If temperature does not increase more than 5°F, compare discharge air temperature, suction and discharge pressures with values in the performance chart corresponding with the ambient temperature.
7. If discharge air temperature fails to meet specifications further diagnosis of air conditioning system should be performed.