Performance Test Diagnosis
INSUFFICIENT COOLINGTrouble Diagnosis Procedure for Insufficient Cooling
Performance Test Diagnosis Part 1:
Performance Test Diagnosis Part 2:
Performance Test Diagnosis
The Nissan A/C system uses a thermal expansion valve to provide a restriction which causes a pressure change and also controls refrigerant flow through the evaporator.
The best way to diagnose a condition in the refrigerant system is to note the system pressures (shown by the manifold gauges) and the clutch cycle rate and times. Then, compare the findings to the charts.
- The system pressures are low (compressor suction) and high (compressor discharge).
- A clutch cycle is the time the clutch is engaged plus the time it is disengaged (time on plus time off).
- Clutch cycle times are the lengths of time (in seconds) that the clutch is ON and OFF.