Radiator Fan Circuit Troubleshooting

Radiator Fan Circuit Troubleshooting
1. Check the No. 4 (20A) fuse in the under-hood fuse/relay box, and the No. 14 (10A) fuse in the under-dash fuse/relay box.
Is the fuse (s) OK?
YES - Go to step 2.
NO - Replace the fuse (s) and recheck.
2. Remove the radiator fan relay from the under-hood fuse/relay box, and test it.
Is the relay OK?
YES - Go to step 3.
NO - Replace the radiator fan relay.





3. Measure the voltage between the No. 1 terminal of the radiator 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 radiator fan relay 4P socket with a jumper wire.
Does the radiator fan run?
YES - Go to step 5.
NO - Go to step 6.





5. Disconnect the jumper, and turn the ignition switch ON (II). Check for voltage between the No. 3 terminal of the radiator fan relay 4P socket and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Check for an open in the wire between the under-hood fuse/relay box and under-dash fuse/ relay box.
6. Disconnect the radiator fan motor 2P connector.





7. Check for continuity between the No. 2 terminal of the radiator fan relay 4P socket and the No. 2 terminal of the radiator fan motor 2P connector.
Is there continuity?
YES - Go to step 8.
NO - Repair open in the wire between the underhood fuse/relay box and the radiator fan motor 2P connector terminal No. 2.





8. Check for continuity between the No. 1 terminal of the radiator fan motor 2P connector and body ground.
Is there continuity?
YES - Replace the radiator fan motor.
NO - Check for an open in the wire between radiator fan motor 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G302.
9. Reinstall the radiator fan relay.
10. Disconnect the radiator fan switch 2P connector.





11. Connect the No. 1 and No. 2 terminals, of the radiator fan switch 2P connector with a jumper wire.
Does the radiator fan run?
YES - Replace the radiator fan switch.
NO - Go to step 12.





12. Remove the jumper wire, and measure the voltage between the No. 2 terminal of the radiator fan switch connector and body ground.
Is there battery voltage?
YES - Check for an open in the wire between radiator fan switch 2P connector terminal No. 1 and body ground. If the wire is OK, check for a poor ground at G302.
NO - Repair open in the wire between the radiator fan switch terminal No. 2 and the under-hood fuse/relay box.