Operation CHARM: Car repair manuals for everyone.

Compressor Clutch Circuit

Compressor Clutch Circuit Troubleshooting

1. Check the No. 19 (20 A) fuse in the under-hood fuse/relay box and the No. 16 (7.5 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.

2. Check the engine coolant temperature, the throttle position sensor, and the idle speed (use the Honda PGM Tester PGM-FI data list if possible).

Is the coolant temperature above normal, the throttle position sensor reading too high, or the idle speed to low?

YES - Troubleshoot and repair the cause of the high engine coolant temperature, high throttle position sensor reading, or low idle speed.

NO - Go to step 3.

3. Remove the compressor clutch relay from the under-hood fuse/relay box, and test it.

Is the relay OK?

YES - Go to step 4.

NO - Replace the compressor clutch relay.




4. Measure the voltage between the No.1 terminal of the compressor clutch relay 4P socket and body ground.

Is there battery voltage?

YES - Go to step 5.

NO - Replace the under-hood fuse/relay box.




5. Connect the No. 1 and No. 2 terminals of the compressor clutch relay 4P socket with a jumper wire.

Does the compressor clutch click ?

YES - Go to step 6.

NO - Go to step 15.

6. Disconnect the jumper wire.
7. Turn the ignition switch ON (II).




8. Measure the voltage between the No. 4 terminal of the compressor clutch relay 4P socket and body ground.

Is there battery voltage?

YES - Go to step 9.

NO - Repair open in the wire between the No. 16 fuse in the under-dash fuse/relay box and the compressor clutch relay.

9. Turn the ignition switch OFF.
10. Reinstall the compressor clutch relay.
11. Make sure the A/C switch is OFF.
12. Turn the ignition switch ON (II).




13. Using the backprobe set, measure the voltage between the No. 17 terminal of ECM connector A (32P) and body ground with the ECM connectors connected.

Is there battery voltage?

YES - Go to step 14.

NO - Repair open in the wire between the compressor clutch relay and the ECM.




14. Using the backprobe set, measure the voltage between the No. 27 terminal of ECM connector A (32P) and body ground with the ECM connectors connected.

Is there battery voltage ?

YES - Check for loose wires or poor connections at ECM connector A (32P). If the connections are good, substitute a known-good ECM, and recheck. If the symptom/indication goes away, replace the original ECM.

NO - Repair open in the wire between the ECM and the A/C pressure switch.

15. Disconnect the jumper wire.
16. Disconnect the compressor clutch IP connector.




17. Check for continuity between the No. 2 terminal of the compressor clutch relay 4P socket and the No. 1 terminal of the compressor clutch IP connector.

Is there continuity?

YES - Check the compressor clutch clearance, the thermal protector, and the compressor clutch field coil.

NO - Repair open in the wire between the compressor clutch relay and the compressor clutch.