A/C Performance Testing

Performance Temperature Chart:

Air temperature in shop should be at least 70 degrees when performing this test.
1. Connect manifold gauge set and tachometer.
2. Set A/C controls to Max A/C, temperature lever to cool, and blower on High.
3. Start engine and adjust speed to 1000 RPM with compressor clutch engaged.
4. Engine should be warmed up with vehicle doors and windows closed.
5. Place thermometer in left center A/C air outlet. Run engine for 5 minutes to allow temperatures to stabilize. Compressor clutch may cycle.
6. After 5 minutes, note discharge air temperature. If compressor clutch is cycling, read thermometer before clutch disengages, then compare discharge temperature to performance temperature chart.
7. Open hood and disconnect gray vacuum line from heater control valve. Valve arm should move as line is disconnected. Plug vacuum line.
8. After an additional 2 minutes of operation, read temperature again. If temperature increase is more than 5°F, check blend door for correct operation. If temperature increase is no more than 5°F, compare discharge air temperature, suction and discharge pressures with values in performance chart corresponding to ambient temperature. Reconnect gray vacuum line.
9. If discharge temperature does not meet specifications in chart, refer to applicable "Group".