Dakota Quad Cab 4WD V6-3.9L VIN X (2001)
Low Pressure Sensor / Switch: Testing and Inspection
Before performing diagnosis of the loss of charge switch, be certain that the switch is properly installed on the accumulator fitting. If the switch is too
loose it may not open the Schrader-type valve in the accumulator fitting, which will prevent the switch from correctly monitoring the refrigerant system
pressure. Remember that lower ambient temperatures during cold weather will open the switch contacts and prevent compressor operation due to the
pressure/temperature relationship of the refrigerant. Also verify that the refrigerant system has the correct refrigerant charge.
1. Disconnect and isolate the battery negative cable.
2. Unplug the loss of charge switch wire harness connector from the switch on the accumulator fitting.
3. Install a jumper wire between the two cavities of the loss of charge switch wire harness connector.
4. Connect a manifold gauge set to the refrigerant system service ports.
5. Connect the battery negative cable.
6. Place the heater-A/C mode control switch knob in any A/C position and start the engine.
7. Check for continuity between the two terminals of the low pressure cycling clutch switch. There should be continuity with a suction pressure
reading of 48-89 kPa (7-13 psi) or above, and no continuity with a suction pressure reading of 48-89 kPa (7-13 psi) or below. If OK, test and
repair the A/C switch sense circuit as required. If not OK, replace the faulty switch.
