DTC P0645: A/C Clutch Relay Circuit: Testing
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition on, engine not running. With the DRBIII® scan tool, actuate the A/C clutch relay. Is the A/C clutch relay operating? If yes, see INTERMITTENT CONDITION under SELF-DIAGNOSTIC SYSTEM. If no, go to next step.
- Turn the ignition off. Remove the A/C clutch relay from the PDC. Ignition on, engine not running. Using a 12-volt test light connected to ground, probe the (F12) fused ignition switch output circuit. Does the test light illuminate brightly? If yes, go to next step. If no, repair the open or short to ground in the (F12) fused ignition switch output circuit.
- Turn the ignition off. Measure the resistance of the A/C clutch relay coil. Is the resistance 60-80 ohms? If yes, go to next step. If no, replace the A/C clutch relay.
- Disconnect the PCM harness connectors. Measure the resistance of the (C13) A/C clutch relay control circuit from the PDC to the appropriate terminal of the Miller Special Tool (8815). Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the (C13) A/C clutch relay control circuit.
- Measure the resistance between ground and the (C13) A/C clutch relay control circuit in the PDC. Is the resistance below 5.0 ohms? If yes, repair the short to ground in the (C13) A/C clutch relay control circuit. If no, go to next step.
- Using the wiring diagram as a guide, inspect the wire harness and connectors. Visually inspect the related wire harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect both the component and the PCM connectors. Pay particular attention to all power and ground circuits. If there are no possible causes remaining, replace and program the PCM. See PROGRAMMING .
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool (8815) to perform diagnosis.
NOTE:
Before continuing, disconnect the PCM harness connectors and check the related wiring terminals for corrosion, damage or terminal push out. Repair as necessary.