RAM 2500 Van V8-5.9L VIN Z (1997)
Evaporator Temperature Sensor / Switch: Testing and Inspection
Fig 22 Fin Sensing Cycling Clutch Switch
Fig 4 Fin Sensing Cycling Clutch Switch
FIN SENSING CYCLING CLUTCH SWITCH
Use a volt/ohmmeter to test the switch. Verify that the refrigerant system has the correct refrigerant charge. Check that both the low and high pressure
cut-off switches are functional, and confirm that the compressor clutch is operational before testing the cycling clutch switch.
1. Set the ignition switch in the On position and the heater-A/C mode control switch in any A/C position. Check for battery voltage at the fused
ignition switch output (run/start) circuit cavity of the fin sensing cycling clutch switch wire harness connector. If OK, go to Step 2. If not OK,
repair the open circuit to the fuseblock module as required.
2. With the ambient temperature between 20 - 30°C (68° - 90°F), start the engine and run the air conditioning system. The compressor clutch should
cycle on and off two to three times per minute. If the clutch fails to cycle at this rate in these temperatures, replace the faulty cycling clutch switch.
NOTE: If the ambient temperature is above 32°C (9O°F) the compressor clutch may stay engaged and not cycle due to the high heat load. This
condition is normal.