RAM 2500 Van V8-5.9L VIN Z (1997)
High Pressure Sensor / Switch: Description and Operation
Fig 20 Compressor Cut-Off Switches
HIGH PRESSURE CUT-OFF SWITCH
The high pressure cut-off switch is located on the discharge line near the condenser. This switch is connected in series between the fin sensing
cycling clutch switch and the Powertrain Control Module (PCM). This switch prevents compressor operation when the discharge line pressure
approaches high levels.
When the discharge line pressure rises above 3,100 - 3,375 kPa (450 - 490 psi) the switch contacts open and interrupt the A/C request signal
circuit to the PCM. The PCM responds by de-energizing the compressor clutch relay, which will cause the compressor clutch to disengage. The
switch will close again when the pressure drops to 1,860 - 2,275 kPa (270 - 330 psi).
The high pressure cut-off switch is a factory-calibrated unit. The switch cannot be adjusted or repaired and, if faulty or damaged, it must be
replaced.
