A/C Compressor Clutch Circuit Troubleshooting

A/C Compressor Clutch Circuit Troubleshooting

1. Check the No. 1 (30 A) fuse in the under-hood fuse/relay box, and the No. 14 (10 A) fuse in the under-dash fuse/relay box.

Are the fuses OK?
YES - Go to step 2.

NO - Replace the fuse(s), and recheck. If either fuse blows again, check for a short in the No. 1 (30 A) or No. 14 (10 A) fuse circuits.


2. Connect the HDS to the DLC.

3. Start the engine.

4. Turn on the A/C on the heater control panel.

5. Using the HDS, confirm the following values in the PGM-FI Data List at idle.





Are all the values within specifications?
YES - Go to step 6.

NO - Troubleshoot the value that is not within the specifications.


6. Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it. Testing and Inspection

Is the relay OK?
YES - Go to step 7.

NO - Replace the A/C compressor clutch relay.


7. Measure the voltage between terminal No. 2 of the A/C compressor clutch relay 4P socket and body ground.

Is there battery voltage?
YES - Go to step 8.

NO - Replace the under-hood fuse/relay box. Under-Hood Fuse/Relay Box Removal and Installation






8. Connect terminals No. 1 and No. 2 of the A/C compressor clutch relay 4P socket with a jumper wire.

Does the A/C compressor clutch click?
YES - Go to step 9.

NO - Go to step 17.






9. Disconnect the jumper wire.

10. Turn the ignition switch to ON (II).

11. Measure the voltage between terminal No. 3 of the A/C compressor clutch relay 4P socket and body ground.

Is there battery voltage?
YES - Go to step 12.

NO - Repair open in the BLK/YEL wire between the No. 14 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay socket.






12. Turn the ignition switch to LOCK (0).

13. Reinstall the A/C compressor clutch relay.

14. Make sure the A/C switch is OFF.

15. Turn the ignition switch to ON (II).

16. Using the backprobe set, measure the voltage between terminal No. 18 of ECM/PCM connector E (31P) and body ground with the ECM/PCM connectors connected.

Is there battery voltage?
YES - Check for loose wires or poor connections at ECM/PCM connector E (31P). If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM. Service and Repair

NO - Repair open in the wire between the A/C compressor clutch relay and the ECM/PCM.






17. Disconnect the jumper wire.

18. Disconnect the A/C compressor clutch 1P connector.

19. Check for continuity between terminal No. 1 of the A/C compressor clutch relay 4P socket and terminal No. 1 of the A/C compressor clutch 1P connector.

Is there continuity?
YES - Check the A/C compressor clutch clearance, and the A/C compressor clutch field coil. Testing and Inspection

NO - Repair open in the wire between the A/C compressor clutch relay socket and the A/C compressor clutch.