Car cooling fan problems

Cooling fan not working? Here's what to do

Your car’s cooling fan, or radiator fan, plays an important job in keeping your engine cool. If it stops working, your engine could overheat and be damaged.

Here’s how to tell if your cooling fan isn’t working, what you should do about it and what the problem might be.

Car overheating

How does a car’s cooling fan work?

When you're driving, air flows through the car radiator to keep your engine a normal temperature. But if you stop, for example in a traffic jam, your engine has to use an electric cooling fan to force air through the radiator.

The fan is temperature-controlled to make sure that the engine gets enough cool air to avoid overheating.


How do I know if the fan isn’t working?

Many modern cars don't have a temperature gauge, but there'll be a light to tell you if the engine's overheating.

If a red or yellow temperature icon lights up on your dashboard, you should stop as soon as it’s safe to do so. You might also see a warning message on the dashboard display.

A yellow light probably means that the coolant level is low. A red light means that your engine's overheating.


What happens if the cooling fan stops working?

If your cooling fan stops working, your engine could overheat. This could cause damage to your engine parts.

It’s a serious issue and needs to be looked at by a garage.


What should I do if my cooling fan breaks?

If the red or yellow temperature light comes on, you need to:

  • Pull over as soon as it’s safe to do so.
  • Turn the engine off.
  • Get your car checked by a garage or contact us for help.

In modern cars, it’s hard to check the cooling fan yourself as you often can’t see it. And if it has stopped working, you’ll need a professional to repair it for you.

That’s why it’s best to take your car to a garage. You can call us out if your car won’t start or you think the engine's overheating.


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What's wrong with my cooling fan?

Your mechanic will look for one these common cooling fan faults:

Blown fuse

As the radiator fan is electrical, the problem could be with the fuse.

Your car’s manual should show where the fuse for the cooling system is. If the fuse has gone, the mechanic will need to replace it right away.

Faulty temperature sensor

On most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor.

If it’s not working, the fan won’t turn on when it needs to, which means the engine might overheat.

Defective fan relay

The fan relay controls the power to the cooling fan. If there’s an issue with the relay, the fan will be affected.

It may cause the fan to cut in and out, or not come on at all.

A wiring issue

Faulty wiring could be to blame. The mechanic will check to see if all the wires to the fan are properly connected and in working order.

Something wrong with the fan motor

If the motor that drives the fan is faulty, then a new motor will have to be fitted.

Low coolant level

Check the engine coolant level. If your engine coolant’s too low, it means that the cooling fan will have to work harder to keep the engine at a normal temperature.

To check the level, look for the coolant expansion tank in the engine bay. There are usually two marks on it – a minimum and maximum level mark. The coolant level should always be between these 2 marks.



Published: 13 July 2017 | Updated: 15 April 2020 | Author: The AA

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