Radiator Fan Circuit Troubleshooting

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

1.Check the No. 11 (30A) fuse in the under-hood fuse/relay box, and the No. 30 (7.5A) fuse in the under-dash fuse/relay box.

Is the fuse(s) OK?


YES - Go to 2.


NO - Replace the fuse(s) and recheck.n


2.Remove the radiator fan relay from the under-hood fuse/relay box, and test it.

Is the relay OK?


YES - Go to 3.


NO - Replace the radiator fan relay.n


3.Measure the voltage between radiator fan relay 4P socket terminal No. 2 and body ground.

Is there battery voltage?


YES - Go to 4.


NO - Replace the under-hood fuse/relay box.n

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 5.


NO - Go to 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 9.


NO - Check for an open in the wire between the under-hood fuse/relay box and under-dash fuse/relay box.n

6.Disconnect the radiator fan motor 2P connector.

7.Check for continuity between radiator fan relay 4P socket terminal No. 1 and radiator fan motor 2P connector terminal No. 2.

Is there continuity?


YES - Go to 8.


NO - Repair open in the wire between the under-hood fuse/relay box and radiator fan motor 2P connector terminal No. 2.n


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.n


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.n

9.Reinstall the radiator fan relay.

10.Disconnect the radiator fan switch 2P connector.

11.Connect radiater 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.n


NO - Go to 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.n


NO - Repair open in the wire between radiator fan switch 2P connector terminal No. 2 and the under-hood fuse/relay box.n