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Compressor Clutch Diode HVAC: Service and Repair

NOTE: If the vehicle is equipped with dual batteries (diesel engine), be sure to disconnect the negative battery cable from both batteries.




1. Disconnect and isolate the negative battery cable(s).
2. Remove the diode from the wire harness. Note the direction of current flow (1). The band located on the end of the diode (2) indicates current flow through the diode.
3. Remove the insulation from the wires in the harness. Only remove enough insulation to solder in the new diode.
4. Install the new diode in the wire harness, making sure current flow is correct. If necessary refer to the appropriate wiring diagram for current flow. Diode as shown in the wiring diagram (3).

CAUTION: Do not use acid core solder when installing a new diode. Acid core solder will corrode the diode connections within the harness, which can cause A/C compressor clutch failure.

5. Solder the connections together using rosin core type solder only.
6. Tape the new diode to the harness using electrical tape. Make sure the diode is completely sealed from the elements.
7. Reconnect the negative battery cable(s).