Top 5 Radiator Fan Not Working Symptoms

Radiator Fan Not Working Symptoms

Signs of the radiator fan not working range from loud noise in your car’s engine to engine overheating. In extreme cases, you might spot damages in your cooling system, or your engine can break down.

You don’t need to wait until your engine breaks down. You can avert great danger by rectifying the issue before it escalates.

Let’s discuss the most common radiator fan not working signs and what to do about them!

Radiator Fan Not Working Symptoms

You can know that your radiator fan is bad when you start noticing strange occurrences in your cooling system.

There are chances that you don’t know how to figure this out. Here are the most common signs that will help you know that your radiator fan is faulty.

1. Radiator Fan Not Working

The first symptom that should tell you that your radiator fan is not working is that the radiator fan won’t come on.

Your radiator fan works in line with your air conditioning system. These fans should come on when you need to regulate your car's temperature.

The radiator fan should come on when your car’s engine coolant reaches 200 degrees Fahrenheit. You can easily figure out that your radiator fan is not coming on by doing the following:

  • Turn on your car, and rev the engine for a while without turning on the A/C.
  • Check if your radiator fan comes on when your car has reached the average operating temperature. If it doesn’t, know that your radiator fan is not working.

2. Engine Overheating

Another way to know that your radiator fan is not working is that your engine will start overheating. Engine overheating is one of the major symptoms of a radiator fan that is not working.

The primary function of a radiator fan is to control temperature and optimize heat. When the fan fails, there is no way to keep the coolant at the appropriate temperature, so your engine will start running hot.

3. Strange and Loud Noise

You can tell that your radiator fan is not working from the strange and loud noise from your radiator system. A bad radiator fan produces a loud whirring noise. This usually occurs when the fan motor or clutch spoils.

The noise will increase as you rev your engine and increase speed. Strange and loud radiator noise can occur because the fan blades are no longer working in harmony.

4. Bad AC Performance

Because the radiator fan is a major component of your AC system, any damage to the fan will affect your AC. One of the ways to tell that your radiator fan is not working is when your AC starts misbehaving and your car interior is hot.

5. Temperature Warning Light Comes on

We’ve explained that a bad radiator fan will cause your car to overheat. This will trigger a temperature warning light, and sometimes a check engine light will come on.

The temperature warning light will come on because your car’s engine is gradually recording abnormal temperatures.

In this scenario, you can best turn off your car and allow the engine to cool off while you inspect and fix the radiator fan.

What Happens if You Drive with a Damaged Radiator?

We wouldn’t wish your radiator fan would stop working, but it does not harm if you understand what will happen if it stops working.

Here are a few things that will happen if your radiator fan stops working:

It would be best if you considered fixing the radiator fan when you noticed it has stopped working. A few-dollar repair will save you a truckload of damages and increased cost.

How Do I Check if My Radiator Fan Is Working?

We understand that you want to check if your radiator fan is still working. That’s an excellent idea. This will help you figure out the next line of action to take in case your radiator fan is bad.

Here’s a rundown of how to check if your radiator fan is working:

Check the type of radiator fan that your car has.

You must determine if your radiator fan runs on a manual or electric operation. Not like this primarily matters, but it will help you determine the maintenance or service protocol if anything goes wrong. We will look for the wire connections if it’s an electrical radiator fan.

Turn on your car and run the AC system to the highest speed.

Now’s the time to tell if your radiator fan is working. Get your car to start working, run a temperature as high as possible without turning on your AC, and check if the fan is spinning. If the fan is not spinning, there are no two ways. Your radiator fan is not working.

Do some testing.

Many people assume that a bad fan motor is a major reason a radiator fan will not stop working. It always goes beyond that. Get a voltmeter and test the wires and connections.

Run through each electrical connection in the radiator fan to see where power is and where the power supply is cut off. The voltmeter should give the volt readings to determine the state of your radiator fan.

A good radiator fan should have a reading of up to 12 volts. Are there no readings? Check the fuse and ensure that they are properly fitted.

What if they are manual radiator fans?

Do some manual inspection.

If you have a manual radiator fan and there is no need to check the wires, you should physically inspect the radiator. Check the fastening, bolts, support, and tension. Ensure that everything is in good shape.

Check the clutch and, if there is any, the belt. Replace any part that is not working properly.


Radiator fan not working is like a ticking bomb waiting to explode. The best you can do is to fix the radiator fans as soon as you can. The radiator fan is a crucial part of your car’s cooling system.

When the radiator fan goes bad, there are irregularities in your car’s ability to maintain temperature. You must contact a technician or take your car for repairs when you spot any bad radiator fan symptoms.

Frequently Asked Questions

Can I drive my car if the radiator fan is not working?

Yes. You can drive your car if the radiator fan is not working, but we advise against that. If you constantly keep it in motion, you can survive without a radiator fan, but who will want to take that risk? What if you must beat the red traffic light or traffic congestion downtown?

Should the radiator fan run when AC is on?

Yes, the radiator is directly tied to your AC as they are part of your car’s cooling system. They should come on the moment you switch on the AC.

How long does it take for the radiator fan to come on?

It should take 15 to 20 minutes for the radiator fan to come on. The operation of the radiator fan is tied to engine thermostats.

Can a bad radiator affect AC?

Yes. The AC handles the process of heat transfer while radiators handle heat exchange. If the heat exchange system is bad, the AC will be affected. The AC system comprises two radiators: the evaporator and the condenser coil. When the evaporator absorbs heat, it is the duty of the condenser to release it. If the radiator is bad, there is no way to let out heat. This leaves the AC compressor with no option but to shut it off due to high pressure.