Radiator Fan Circuit

Radiator Fan Circuit Troubleshooting

NOTE: Before beginning this troubleshooting procedure, refer to the symptom troubleshooting index. Testing and Inspection

1. Check the No. 11 (20A) fuse in the under-hood fuse/relay box, and the No. 30 (7.5A) 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 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 radiator fan relay 4P socket terminal No. 2 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Replace the under-hood fuse/relay box.





4. Connect radiator fan relay 4P socket terminal No. 1 and No. 2 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 radiator fan relay 4P socket terminal No. 3 and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Check for an open in the BLK/YEL wire between the under-hood fuse/relay box and underdash fuse/relay box.
6. Disconnect the radiator fan motor 2P connector.





7. Check for continuity between radiator fan relay V socket terminal No. 1 and radiator fan motor 2P connector terminal No. 2.
Is there continuity?
YES - Go to step 8.
NO - Repair open in the wire between the underhood fuse/relay box and radiator fan motor 2P connector terminal No. 2.





8. Check for continuity between radiator fan motor 2P connector terminal No. 1 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 G301.
9. Reinstall the radiator fan relay.
10. Disconnect the radiator fan switch 2P connector.





11. Connect radiator fan switch 2P connector terminal No. 1 and No. 2 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 radiator fan switch 2P connector terminal No. 2 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 G301.
NO - Repair open in the wire between radiator fan switch 2P connector terminal No. 2 and the underhood fuse/relay box.