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Why Does My Radiator Fan Stay On When My Car Is Off?

It’s normal for some vehicles to have a fan run for a few minutes after the car is shut off, generally to keep the engine cool. However, if the fan is running for an extended period, the fan itself can become damaged due to overuse. … It’s possible you may have a module or relay failing in your car.

Why does my cooling fan stay on?

Cooling fans stay on at all times

If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

How do I stop my radiator fan from running?

  1. Open the hood and locate the fuse relay box on the driver’s fenderwell. Remove the lid.
  2. Look on the inside of the lid and for the mapping of the fuses and relays with their location. Pull the cooling fan relay out of the box. Replace the cooling fan relay with a new one.

Should radiator fan turn on when AC is off?

Both radiator fans should always run when the AC compressor is engaged. To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches about 200 to 230 degrees.

How do I know if my cooling fan relay is bad?

  1. The engine runs hot or overheats. …
  2. The cooling fans don’t work. …
  3. The cooling fans keep running. …
  4. Warning lights. …
  5. Poor air conditioning performance. …
  6. Swapping Relays. …
  7. Measuring the Relay Coil’s Resistance. …
  8. Listening for Noises.

Why is my car overheating but it has coolant in it?

In general, it’s because something’s wrong within the cooling system and heat isn’t able to escape the engine compartment. The source of the issue could include a cooling system leak, faulty radiator fan, broken water pump, or clogged coolant hose.

Should my radiator fan always be on?

Fan Trigger

The engine temperature should trigger the fan to turn on. It will also turn the fan off once the engine has cooled to under 200 degrees. You may have heard of a part called the radiator fan switch or temperature fan switch. This is linked to a thermostat and works much like your home’s HVAC system.

What does a bad radiator fan sound like?

In some cases, when your radiator cooling fan clutch fails, it will develop a whirring or clicking noise. The noise could result from a bearing that is out of place or a bent fan blade that is touching other components.

Can low coolant cause fan to stay on?

Troubleshooting Tips

If the fan turns off, that means the relay is at fault. Furthermore, check for low coolant levels and possible leaks that may be causing it. Usually, a low coolant will equate to a hotter engine. Therefore, it will activate the fan more often.

What if the radiator fan turns on only when the AC is on but overheats when is off?

The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. … When the vehicle has the AC on, the engine needs extra help cooling so the ECU commands the fan to be on any time the AC is on.

Can a bad thermostat cause radiator fan not to work?

Broken Thermostat

Thermostats are known to go bad and cause all sorts of cooling issues. … If this thermostat doesn’t open when the engine reaches the working temperature, the coolant will stay inside the engine block and the engine will start to overheat. This will result in the radiator fan not working.

How much does it cost to fix a radiator fan?

The average cost for a replacement fan is between $634 and $789. Labor costs are between $102 and $130 while parts are between $532 and $659. Taxes and fees are not included in the estimate.

How do you check a fan relay?

  1. Look at the markings on top or side of the relay case and locate the two control circuit terminals, which connect to the relay’s coil, and the two power circuit terminals, which let electrical current pass to the fan. …
  2. Connect the leads of an ohmmeter to the power terminals on the relay.

How do you check if cooling fans are working?

  1. Determine whether your radiator fan is manual or electric. …
  2. To check an electric radiator fan, start the car and let it get up to the temperature where the fan normally kicks on.
  3. Use the volt meter to test if there is power to the wires. …
  4. Normal voltage for a radiator fan is around 12 volts.

What causes a radiator fan to not turn on?

Six things may prevent an electric cooling fan from coming on: Defective temperature switch, coolant sensor or other sensor. Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan) Faulty fan relay.

What are signs of a bad thermostat?

  • The temperature gauge reads high and the engine overheats.
  • The temperature changes erratically.
  • The vehicle’s coolant leaks around the thermostat or under the vehicle.