Cooling Fan Not Turning On: Signs and Diagnosis
Key Takeaway
Cooling fan should kick on when the engine gets hot. If it doesn't, here's how to diagnose it.
Signs the Cooling Fan Isn't Working
| Sign | Details |
|---|---|
| Overheating at idle/low speed | No airflow without fan |
| Fine at highway speed | Ram air provides cooling |
| AC works poorly at idle | Condenser fan often shared |
| Fan never spins when engine is hot | Visual confirmation |
Common Causes
| Cause | Fix Cost |
|---|---|
| Blown fan fuse/relay | $5 – $20 |
| Failed fan motor | $200 – $400 |
| Coolant temp sensor (fan trigger) | $50 – $150 |
| Wiring damage | $50 – $200 |
| Failed fan control module | $100 – $300 |
Quick Test
1. Turn on the AC — most vehicles activate the fan when AC is on.
2. If the fan runs with AC, the motor is good — it's the temp sensor or relay.
3. If the fan doesn't run with AC, check the fuse first, then the motor.
ProHow Steer Helps
Steer monitors coolant temperature and identifies overheating patterns consistent with fan failure (overheats at idle, fine at speed).
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