Fans Low Speed Circuit Troubleshooting
Radiator and Condenser Fans Low Speed Circuit Troubleshooting1. 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. Remove the condenser fan relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the condenser fan relay.
3. Measure the voltage between the No. 1 terminal of the condenser fan relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.
4. Connect the No. 1 and No. 2 terminals of the condenser fan relay 4P socket with a jumper wire.
Does the condenser fan run?
YES - Go to step 5.
NO - Go to step 13.
5. Disconnect the jumper wire.
6. Turn the ignition switch ON (II).
7. Measure the voltage between the No. 4 terminal of the condenser fan relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Repair open in the wire between the No. 16 fuse in the under-dash fuse/relay box and the condenser fan relay.
8. Reinstall the condenser fan relay.
9. Remove the A/C diode from the left side of dash.
10. On the A/C diode, check for current flow in both directions between the No. 1 and No. 2 terminals, and between the No. 2 and No. 3 terminals.
Does current flow match the diagram?
YES - Go to step 11.
NO - Replace the A/C diode.
11. Turn the ignition switch ON (II).
12. Measure the voltage between the No. 2 terminal of the A/C diode 3P connector and body ground.
Is there battery voltage?
YES - Repair open in the wire between the A/C diode and the A/C pressure switch.
NO - Repair open in the wire between the condenser fan relay and the A/C diode.
13. Disconnect the jumper wire.
14. Reinstall the condenser fan relay.
15. Disconnect the condenser fan 2P connector.
16. Turn the ignition switch ON (II), then turn the A/C and fan switches ON.
17. Measure the voltage between the No. 2 terminal of the condenser fan 2P connector and body ground.
Is there battery voltage?
YES - Go to step 18.
NO - Repair open in the wire between the condenser fan relay and the condenser fan.
18. Turn the A/C and fan switches OFF, then turn the ignition switch OFF.
19. Reconnect the condenser fan 2P connector.
20. Connect the No.1 terminal of the condenser fan 2P connector to body ground with a jumper wire.
21. Turn the ignition switch ON (II), then turn the A/C and fan switches ON.
Does the condenser fan run?
YES - Go to step 22.
NO - Replace the condenser fan motor.
22. Turn the A/C and fan switches OFF, then turn the ignition switch OFF.
23. Disconnect the jumper wire.
24. Remove the fan control relay from the multi-relay box, and test it.
Is the relay OK?
YES - Go to step 25.
NO - Replace the fan control relay.
25. Turn the ignition switch ON (II), then turn the A/C and fan switches ON.
26. Measure the voltage between the No. 1 terminal of the fan control relay 5P socket and body ground.
Is there battery voltage?
YES - Go to step 27.
NO - Repair open in the wire between the condenser fan and the fan control relay.
27. Turn the A/C and fan switches OFF, then turn the ignition switch OFF.
28. Disconnect the radiator fan 2P connector.
29. Check for continuity between the No. 4 terminal of the fan control relay 5P socket and the No. 2 terminal of the radiator fan 2P connector.
Is there continuity?
YES - Go to step 30.
NO - Repair open in the wire between the fan control relay and the radiator fan.
30. Check for continuity between the No. 1 terminal of the radiator fan 2P connector and body ground.
Is there continuity?
YES - Replace the radiator fan motor.
NO - Check for an open in the wire between the radiator fan and body ground. If the wire is OK, check for poor ground at G301.