Last Updated on August 5, 2023 by tawhid

The radiator fan will turn on when the coolant temperature exceeds a certain threshold. The specific temperature will vary depending on the vehicle, but is typically around 200 degrees Fahrenheit. When the engine coolant reaches this temperature, the radiator fan will turn on to help cool it down.

Most people don’t think about their radiator fan until it’s too late. The radiator fan is responsible for cooling the engine and keeping the temperature down. However, it can only do its job properly if it’s turned on.

So when does the radiator fan turn on? The answer varies depending on the make and model of your car. Some cars have a sensor that turns the fan on when the engine gets hot.

Others have a switch that you need to turn on manually. And some cars have a combination of both. If your car has a sensor, it will usually be located near the radiator or in the engine bay.

If your car has a switch, it will usually be located near the thermostat or in the dash. Either way, make sure you know where it is so you can turn it on when needed. The most important thing to remember is that the radiator fan only needs to be turned on when the engine is hot.

So if you’re driving in cool weather, there’s no need to worry about turning it on.

Should Radiator Fan Turn on When Ac is on

One of the most common questions we get here at Radiator Fan Pros is whether or not the radiator fan should turn on when the AC is on. The answer, unfortunately, isn’t as cut and dry as we would like it to be. In some cases, the fan will turn on when the AC is turned on and in others it won’t.

It really depends on your specific vehicle and how it’s been designed. So, why is there so much confusion surrounding this issue? Well, it has to do with the fact that there are two different types of cooling systems in most vehicles – an engine cooling system and an AC system.

The engine cooling system is responsible for keeping the engine cool, while the AC system keeps the cabin of the vehicle cool. In most cases, these two systems are completely separate from each other. However, in some cases, the engine cooling fans can also be used to help cool down the cabin of the vehicle.

If this is the case with your vehicle, then you’ll likely find that your fan turns on when you turn on your AC. However, if your vehicle doesn’t have this feature, then you probably won’t see your fan turn on when you turn on your AC. At the end of the day, it really comes down to trial and error.

If you’re not sure whether or not your fan should be turning on when you turn on your AC, we recommend experimenting a bit until you figure out what works best for your particular situation.

How Long Does It Take for a Radiator Fan to Turn on

As soon as your engine starts, the radiator fan should start spinning. If it doesn’t, there could be a problem with your cooling system. The radiator fan is responsible for cooling down the engine by drawing air through the radiator fins.

It’s important that the fan is working properly because if the engine overheats, it can cause serious damage. If you notice that your radiator fan isn’t turning on, you should take it to a mechanic to have it checked out. In most cases, the problem can be fixed relatively easily.

However, if the issue is more serious, it could require more extensive repairs.

What Tells the Radiator Fan to Turn on

The radiator fan is an important part of the cooling system in your car. It helps to circulate coolant throughout the engine and prevents the engine from overheating. The fan is controlled by a switch that is located on the thermostat housing.

When the engine temperature gets too high, the switch tells the fan to turn on and start circulating coolant. If the engine temperature gets too low, the switch will tell the fan to turn off.

How to Make Radiator Fan Turn on

Most people don’t know how easy it is to make a radiator fan turn on. With a few simple steps, you can make your fan turn on automatically when the engine gets hot. 1. Get a thermostat switch from your local hardware store.

You’ll need one that’s rated for the wattage of your fan. 2. Mount the switch in a convenient location near the radiator fan. Make sure it’s mounted securely so it doesn’t vibrate loose.

3. Wire the switch into the circuit for the radiator fan. The specific method will vary depending on your vehicle, but most switches will have two wires – one that goes to ground and one that goes to the power side of the fan relay or fuse box. If you’re not sure which wire is which, consult your vehicle’s wiring diagram or an automotive technician friend before proceeding.

4. Once everything is wired up, test the system by starting up your engine and letting it idle for a few minutes until it reaches operating temperature; then check to see if the radiator fan turns on automatically when expected!

Radiator Fan Turns on And off Constantly

If your radiator fan turns on and off constantly, there could be a few different reasons why. First, let’s rule out the possibility that it’s just a loose connection – if that were the case, the fan would either not turn on at all, or it would run continuously. If you’re sure it’s not a loose connection, then it could be a sign that your engine is overheating.

The purpose of the radiator fan is to cool down the engine, so if it’s turning on and off frequently, it means the engine is getting too hot and cooling itself back down again. This is definitely something you’ll want to get checked out by a mechanic as soon as possible, as an overheating engine can cause serious damage.

When Does Radiator Fan Turn on


What Causes Radiator Fan to Turn On?

There are a few different things that can cause your radiator fan to turn on. One of the most common causes is when your engine is running hot. The fan helps to cool down the engine by blowing air over the radiator fins.

If the engine gets too hot, it can damage the internals or even seize up. That’s why it’s important to keep an eye on your temperature gauge and make sure you’re not overheating. Another reason your fan might turn on is if your car is low on coolant.

The coolant level needs to be high enough so that it can circulate properly and keep the engine at a safe temperature. If you’re low, the fan will come on to try and compensate for the lack of coolant. Be sure to check your levels regularly and top off as needed.

Lastly, some cars have an electric fan that comes on when you turn on the A/C. This is because the A/C puts an extra load on the engine and cooling system, so the fan helps to keep everything running smoothly. If your radiator fan turns on more frequently than usual or if it seems like it’s running constantly, there could be an issue with the sensor or switch that controls it.

Have a professional diagnose and repair as needed so you don’t end up with a bigger problem down the road.

Are Radiator Fans Supposed to Run All the Time?

If your engine is running hot, the radiator fans will run all the time to try and cool it down. If your engine is running at a normal temperature, the radiator fans will cycle on and off as needed.

How Do I Know If My Radiator Fan is Working?

If your car has been running hot, or if you’ve noticed that the engine is running hotter than usual, one of the first things you should check is the radiator fan. The radiator fan helps to cool the engine by circulating air through the radiator. If the fan isn’t working properly, it can cause the engine to overheat.

There are a few ways to tell if your radiator fan is not working properly. One way is to simply look at the fan itself. If it’s not spinning, then it’s not doing its job.

Another way to tell is by feeling the temperature of the air coming out of the vents on your car. If it feels significantly hotter than usual, that could be a sign that the fan isn’t working as well as it should be. If you think there may be an issue with your radiator fan, the best thing to do is take your car to a mechanic and have them take a look.

They will be able to diagnose whether or not there is a problem and let you know what needs to be done to fix it.

Does the Radiator Fan Run While Idling?

If your engine is idling and the radiator fan kicks on, that’s normal. The fan helps keep the engine cool when it’s running. If the fan stays on after you turn off the engine, that could indicate a problem with the cooling system.

The radiator fan is vital to keeping your engine cool. It helps circulate air through the radiator to remove heat from the coolant. The coolant then flows back through the engine to absorb more heat.

This process repeats continuously while the engine is running. If the fan doesn’t come on when it should, or if it stays on after you turn off the engine, that could be a sign of a problem. It could mean there’s an issue with the cooling system, such as a leak or blockage.

Or, it could be a sign of an electrical problem with the fan itself. If you notice your radiator fan isn’t working properly, have it checked out by a mechanic right away. They can diagnose and fix any underlying issues before they cause serious damage to your engine.



Radiator fans are designed to keep your engine cool by drawing air through the radiator. They usually turn on automatically when the engine is running and the temperature gets too hot. However, in some cases, you might need to manually turn on the radiator fan.

Here are a few scenarios where you might need to do this: -If your car has been sitting in hot weather for a while, the fan might not come on right away. In this case, you can turn it on manually to help cool down the engine before driving.

-If your car is low on coolant, the fan might not come on even if the engine is getting hot. This is because there isn’t enough fluid flowing through the radiator to absorb heat. Again, turning on the fan manually can help prevent overheating until you can get your car serviced.

-If there’s something blocking airflow through the radiator (like a big bug!), the fan might not be able to do its job properly. In this case, you’ll definitely want to turn it on manually so that your engine doesn’t overheat.

Leave a Reply

Your email address will not be published. Required fields are marked *