Operation CHARM: Car repair manuals for everyone.

Fans High Speed Circuit Troubleshooting

Radiator and Condenser Fans High Speed Circuit Troubleshooting

1. Remove A/C diode C from the right side of dash.




2. Check for current flow in both directions between the No.1 and No.2 terminals of A/C diode C.

Is there current flow in only one direction?

YES - Go to step 3.

NO - Replace A/C diode C.

3. Turn the ignition switch ON (II).




4. Measure the voltage between the No.2 terminal of A/C diode C 2P connector and body ground.

Is there battery voltage?

YES - Go to step 5.

NO - Repair open in the wire between the radiator fan relay and A/C diode C.

5. Turn the ignition switch OFF.
6. Reinstall A/C diode C.
7. Disconnect the A/C pressure switch 4P connector.
8. Turn the ignition switch ON (II).




9. Measure the voltage between the No.2 terminal of the A/C pressure switch 4P connector and body ground.

Is there battery voltage?

YES - Go to step 10.

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

10. Turn the ignition switch OFF.




11. Check for continuity between the No.1 and No.3 terminals of the A/C pressure switch 4P connector.

Is there continuity?

YES - Replace the A/C pressure switch.

NO - Repair open in the wire between the A/C pressure switches A and B.