Radiator Cooling Fan: Testing and Inspection

Radiator Fan High Speed Circuit Troubleshooting

1. Check the No. 3 (30 A) fuse No. 14 (15 A) fuse, and the No. 21 (7.5 A) fuse in the under-hood fuse/relay box.

Are the fuses OK?

YES - Reinstall the fuse(s), then go to step 2.

NO - Replace the fuse(s) and recheck.

2. Disconnect and remove the relay circuit board from the under-hood fuse/relay box and test it.

Is the relay circuit board OK?

YES - Go to step 3.

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

3. Measure the voltage between under-hood fuse/relay box connector terminal C1 and body ground.





Is there battery voltage?

YES - Go to step 4.

NO - Repair open in the wire between under-hood fuse/relay box connector terminal C1 and the No. 3 (30 A) fuse in the under-hood fuse/relay box.

4. Connect under-hood fuse/relay box connector terminals C1 and B2 with a jumper wire.





Does the radiator fan run at high speed?

YES - Go to step 7.

NO - Go to step 5.

5. Test the fan motor.

Is the fan motor OK?

YES - Go to step 6.

NO - Replace the fan motor, and retest.

6. Check for continuity between the radiator fan motor terminal No. 1 and body ground.

Is there continuity?

YES - Repair open in the wire between under-hood fuse/relay box connector B2 and radiator fan motor 2P connector terminal No. 2.

NO - Repair open the wire between the radiator fan motor terminal No. 1 and body ground.

7. Turn the ignition switch to ON (II).
8. Measure the voltage between under-hood fuse/relay box connector terminal B7 and body ground.





Is there battery voltage?

YES - Go to step 9.

NO - Repair open in the wire between under-hood fuse/relay box connector terminal B7 and the No. 21 (7.5 A) fuse in the underhood fuse/relay box.

9. Turn the ignition switch to LOCK (0).
10. Check for continuity between under-hood fuse/relay box connector terminal B11 and the engine control module (ECM)/powertrain control module (PCM) A5.

Is there continuity?

YES - Reinstall the ECM/PCM.

NO - Repair open in the wire between under-hood fuse/relay box connector terminal B11 and the ECM/PCM A5.