Performance Test

1. Place A/C controls on maximum A/C (recirculating air) and blower on high speed.
2. Run engine for ten minutes at 1500 RPM to stabilize system.
3. System must be tested in a ambient temperature of 70-80°F.
4. Connect manifold gauge set.
5. As soon as system is stabilized, record high and low pressure reading.
6. Determine clutch cycle time.
7. Record clutch off time in seconds.
8. Record clutch on time in seconds.
9. Record center register discharge temperature.
10. Determine and record ambient temperature.

Fig. 13 A/C Clutch Cycling Timing Rates Chart:

Fig. 14 A/C Pressure Temperature Chart:

11. Compare test reading with applicable chart, Fig. 13 and 14.
12. If test reading falls within acceptable range, system is operating normally.

Fig. 15 Refrigerant System Clutch Cycle Timing Evaluation Chart (Part 1 Of 2):

Fig. 15 Refrigerant System Clutch Cycle Timing Evaluation Chart (Part 2 Of 2):

13. If test reading falls outside acceptable range, refer to refrigerant system and clutch cycle timing evaluation chart, Fig. 15.
14. After servicing and correcting a refrigerant system problem, repeat this procedure to ensure proper operation of the A/C system. In ambient temperatures above 100°F, compressor clutch will not normally cycle off and, in many instances, clutch will not cycle off when temperatures are above 90°F.