Radiator Fan Circuit Troubleshooting

Radiator Fan Circuit Troubleshooting
Without A/C
1. Check the No. 11 (30 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 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. 1 and body ground.
Is there battery voltage?
YES-Go to step 4.
NO-Replace the under-hood fuse/relay box.





4. Connect a jumper wire between radiator fan relay 4P socket terminal No. 1 and No. 2.
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 the under-dash fuse/relay box.
6. Disconnect the radiator fan connector.





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





8. Check for continuity between radiator fan 2P connector terminal No. 1 and body ground.
Is there continuity?
YES-Replace the radiator fan motor.
NO-Check for an open in the BLK wire between the radiator fan 2P connector 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, then connect a jumper wire between terminal No. 1 and No. 2.
Does the fan run?
YES-Replace the radiator fan switch.
NO-Go to step 11.





11. 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 BLK wire between the radiator fan switch connector and body ground. If the wire is OK, check for a poor ground at G101.
NO-Repair an open in the GRN wire and BLU/RED wire between the radiator fan switch connector and under-hood fuse/relay box.

With A/C
1. Check the No. 11 (30 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES-Go to step 2.
NO-Replace the fuse 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. 1 and body ground.
Is there battery voltage?
YES-Go to step 4.
NO-Replace the under-hood fuse/relay box.





4. Connect a jumper wire between radiator fan relay 4P socket terminal No. 1 and No. 2.
Does the radiator fan run?
YES-Go to step 5.
NO-Repair an open in the BLU/BLK wire between the under-hood fuse/relay box and the radiator fan.





5. Disconnect the jumper wire, 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 6.
NO-Check for an open in the BLK/YEL wire between the under-hood fuse/relay box and the under-dash fuse/relay box.
6. Reinstall the radiator fan relay.





7. Disconnect the radiator fan switch 2P connector, then connect a jumper wire between terminal No. 1 and No. 2.
Does the fan run?
YES-Replace the radiator fan switch.
NO-Go to step 8.





8. Remove the jumper, 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 BLK wire between the radiator fan switch connector and body ground. If the wire is OK, check for a poor ground at G101.
NO-Repair an open in the GRN wire and BLU/RED wire between the radiator fan switch connector and under-hood fuse/relay box.