My Radiator Fan Won’t Turn Off – What Should I Do?

My radiator fan won’t turn off – what should I do? This post is for individuals unsure what to do if their automobile fan refuses to turn off.

This occurs even after you have shut off your engine. Here, you will understand why your automobile fan keeps turning on.

Also, you will learn basic troubleshooting techniques and how to handle when your car’s fan continues turning on even when the engine is off.

So, let’s get started on the topic at hand.

What Is A Radiator Fan?

my radiator fan won't turn off

Before investigating why a radiator fan won’t shut off, let’s first determine what a radiator fan is.

The radiator fan is the part that circulates cooling air through a vehicle’s radiator.

The cooling fan, positioned between the engine and the radiator, is particularly important when the car is stopped or travels too slowly to drive air through the windshield.

Electric cooling fans, which slowed or stopped precisely when required, proved superior to engine fans.

A faulty cooling fan can cause the engine to overheat. These fans are occasionally used to cool the condenser of the cabin air conditioner unit.

My Radiator Fan Won’t Turn Off – What Should I Do?

Various issues might be at play when the radiator fan won’t turn off. If you discover that your automobile fan is not turning off, you should:

  • Unplug and disconnect your automobile battery’s negative terminal
  • Check your coolant level
  • Examine your temp sensor

Should you discover that your automobile fan does not switch off, it’s best to address the problem as quickly as possible so that it does not worsen.

Unplug And Disconnect Your Automobile Battery’s Negative Terminal

In case of your vehicle radiator fan not turning off, you should block your car battery from turning down by detaching and disconnecting the wired connection to the battery’s negative electrode.

The relay is the source of the issue when the negative side of the battery cable is removed, and the automobile fan is turned off.

You may also need to fix the bad fan relay by substituting it with a replacement one with the same pin design. A digital multimeter may be used to test the cooling system relay.

Check Your Coolant Level

To identify why the radiator fan wont shut off, you may also inspect your coolant level to see whether it is insufficient. It would be better if you also looked for any leaks.

Supposing your car’s coolant level is low, your vehicle may overheat. This will activate the vehicle’s cooling system, and the fan won’t turn off.

Examine Your Temperature Sensor

If the fan on your car continues to operate after you have shut off the engine, the coolant temperature sensor may be defective.

So, you need to check it or have a mechanic from auto manufacturing help you.

Why Does My Radiator Fan Keep Running?

The radiator fan is essential to your car’s cooling system and might fail over time. The following are the most typical reasons why your engine fan won’t turn off:

Low Coolant Level

If the fan in your automobile remains running after you switch off the engine, chances are that your coolant level is too low or keeps dropping down.

The fuel pump is a potential culprit behind leaks, and when these leakages occur, your coolant level drops, leaving a hotter engine and causing your fan to run continuously.

Faulty Thermostat Housing

If the housing for the car’s thermostat exhibits evidence of leakage, it might signal trouble.

Faulty Radiator

Your car’s radiator could be a cause of difficulties. If your radiator is broken, your automobile fan may not turn off.

Fractures in the radiator are probably the source of the issue. Your vehicle’s top and bottom radiator hoses are likely to fatigue and strain.

It’s conceivable that the radiator hoses and piping have become corroded.

It will fail instantly once the coolant pipes and hoses become corroded. Whenever this occurs, probably your car fan won’t turn off.

Bad Radiator Fan Relay

Another probable reason for the issue lies in the radiator fan relay. The fan relay controls the current flowing to the cooling system.

The engine’s fan will be affected if there is any problem with the relay.

For instance, the radiator fan relay might become blocked in the on position and cease to function.

Wiring Issue

You should also pay attention to the faulty wiring. A short circuit can trigger the problem, for example, incorrect wiring or damaged wires.

A specialist will verify that all of the connections to the fan are linked and operating correctly to find the problem.

What Are The Symptoms Of A Bad Radiator Fan?

What Are The Symptoms Of A Bad Radiator Fan?

A radiator that isn’t operating correctly will show a variety of symptoms. While this is not an entire list, these are the most often expressed grievances:

Overheating Engine

A frequent symptom of a radiator problem is when your engine begins to overheat.

A broken thermostat might be at blame. If the defective thermostat is closed, the motor will overheat and produce issues.

Coolant Leaks

You may detect coolant fans leaking beneath the vehicle. The liquid might be red, yellow, or green fluid.

When the radiator fails, the coolant level drops, and if there isn’t sufficient antifreeze to keep the engine cool, it might overheat.

Also, the radiator is constructed of plastic and metal.

Because plastic isn’t as sturdy as metal, it’s common for these elements to grow brittle and shatter, resulting in the leak.

Shifting Issues

If you have an integrated transmission cooler, you may experience shifting issues due to coolant contamination. System flaws and mistakes cause this problem.

Fluid Discoloration

Vehicle coolant has different colors; it is often a bright yellow, green, pink, or red liquid. It readily circulates between the coolant passages and the radiator in your vehicle engine.

If your radiator fan wont turn off in car or isn’t working properly, deposits can pollute the coolant, turning it rusty and even resembling oil.

Examine the color of your coolant overflow tank. In case it gets thicker, it might be polluted, and this will cause flow issues and result in a blocked radiator.

In this situation, draining the radiator may be an option.

Exterior Fins Blocked

Radiators require optimum airflow to function properly. The front fin-like tubes are thin tubes that convey heated coolant out from the vehicle.

Air travels through the fins as you drive, lowering the coolant’s temperature.

Airflow can be hampered when these fins get blocked with debris, bugs, leaves, or dirt. The coolant is unable to reduce the temperature to normal.

Many automobiles have enough space for a garden hose to splash out of the radiator and keep the air moving smoothly.

In addition to restricting the airflow, you may have broken or deformed the heatsink fins. They are extremely fragile; dust or flying objects might cause harm.

It’s also possible that you harmed them when installing them or sprayed them with high-pressure water.

Damaged fins can clog the radiator, resulting in vehicle overheating.

The Passenger Heater Is Not Functioning

Another telltale indicator of a faulty radiator is when the heater fails to function properly.

The core of your cabin heater is heated by hot coolant. This produces heated air, which is then blown into your vehicle.

On a chilly winter day, your car may not get enough heat if your radiator is leaking or blocked.

Frequently Asked Questions

What Sensor Controls The Car Fan?

The coolant temp sensor controls the automobile fan. It delivers a signal to the engine’s coolant temperature sensor, which takes input and regulates the cooling fan.

How Does The Temperature Sensor Work?

The coolant temp sensor is frequently situated near the motor thermostat, and the sensor’s tip can be located near the engine coolant.

The sensor measures the temperature emitted by the coolant or the thermostat. After that, the temperature is supplied to the control system.

The car’s computer then uses the temperature input to keep the motor running or adjust how the engine functions. It runs continually to keep the engine temperature at a comfortable level.

Once the control system gets data from the sensor, it instructs the cooling fan to turn it on or off.

Furthermore, it may indicate that a richer fuel combination is required or that the gas recirculation should be turned on.

What Is The Cost Of Changing The Fan In A Car?

The typical cost of changing a radiator fan is $300 to $400. A radiator fan might cost anywhere between $400 and $450. The kind of car determines the price.

Because it is attached directly to the radiator, most radiator fans are simple to access and repair.

If you’re acquainted with automotive tools and how they function, you can replace the radiator fan at home and save money on service.

You should, however, avoid driving a car with a broken radiator fan. Overheating may occur if the fan cannot feed the cool engine air.

The replacement price of the motor is more than the expense of repairing or replacing a broken radiator fan.

Can You Drive With A Radiator Problem?

Driving with a leaking radiator is risky since it might cause your vehicle to overheat. If you’re on the highway and find your engine overheating, pull over right away and let it cool.


To sum up, you can now find the answer to the question of why my radiator fan won’t turn off and what I should do.

We hope our solutions in the post above and other information are useful. Whenever you detect this issue, stop driving as soon as possible and find a garage for help.

See you next time!

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