Why does the radiator fan turn on when the car starts?

The radiator fan is in charge of pulling cool air through the car’s radiator, helping cool off the passengers and keep your ride as comfortable as possible. Let’s find out the function of the radiator fan, the symptoms of a failing radiator fan, and why your radiator fan turns on when the car starts.

When do you turn on the engine cooling fan?

So, extra cooling is not needed, when a cold engine is first started. As a result, the engine cooling fan, does not come on until the engine reaches, normal operating temperature. The fan will then cycle on and off as needed, to maintain the proper coolant temperature.

What makes an engine fan not turn on?

Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan) A wiring problem (blown fuse, loose or corroded connector, shorts, opens, etc.) On most systems; there is a coolant temperature switch that turns the fans on and off.

Where is the motor for the heater blower located?

The motor that turns the blower is called the blower motor. It is located in the dashboard, usually on the opposite side of the steering wheel or inside the engine compartment on the firewall. The blower speed can be adjusted in almost every modern car.

Can a bad fan relay cause an engine to overheat?

However, a bad cooling fan relay isn’t the only culprit for excessively high engine temperatures. Many other issues can cause the engine to run hot or overheat. Rather than uncommonly high engine temps, the driver may notice that the cooling fans have stopped running.

Why does my car fan turn on when it gets too hot?

The temperature sensor is responsible for turning on the cooling fan when the car gets too hot. Defective fan relay. The fan relay is what controls the power to the cooling fans so if there is an issue with it, the fan will be affected. A wiring issue.

Is the cooling fan still running when the engine is off?

That is because it is measuring coolant temperature, not engine temperature. The engine is still much hotter than the coolant. Yes, the engine still puts out heat even when it is off. You want to remove excess heat.

How does the cooling fan relay work on a car?

The cooling fan relay is the relay that controls the engine’s cooling fans. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. The relay will usually be activated once it is detected that the vehicle’s temperature…

Is it normal for a car fan to run when the engine is off?

This is entirely normal. As missileman explained, the fans are removing excess heat from the engine’s cooling system. Some cars allow the fan to run after the key has been removed, some cars don’t. I like the ones that allow the fan to run.

Why does my car heat up when I’m not driving?

If you have an electric cooling fan that isn’t coming on, this can cause your engine to overheat. This fan draws cooler air through your radiator when your car isn’t going fast enough to do the job naturally. You can test this by letting your car idle long enough for the engine to heat up.

What should I do if my radiator fan is not working?

A blown fuse is no big deal, and changing one does not cost a lot of money. If your car’s radiator fan is non-functional, check your car’s user manual and locate the fuse for the radiator fan controller or the fan. The fan itself often uses a big fuse of around 50A, while there might also be a separate small fuse to the fan control module.

Can a broken radiator fan keep your car cool?

A radiator fan has an important role of keeping a vehicle’s engine cool. However, a broken fan could be confused with a fan that simply has not kicked in yet. This is one reason why information on when a radiator fan is suppose to start can be beneficial to vehicle owners. Temperature will often determine the time that a radiator fan starts up.

How can I tell if my radiator fan is working?

When a radiator fan works it usually makes a whirring sound that is easily noticeable. However, the radiator fan does not always start spinning on ignition. The ECU signals the radiator fan to work at the precise time. So, do not worry if the fan doesn’t immediately start working. Visually check the fan if you don’t hear its noise. 1. Broken Fuse

What kind of fan does a rear wheel drive car use?

There are two basic types of radiator fans that will be in your car – either mechanical or electric. The difference between these two kinds of fans can affect why the radiator fan turns on when the car starts. The mechanical radiator fan is generally more common in older, rear-wheel-drive cars.

Where is the relay on a radiator fan?

The fan relay is often located in the engine bay’s fuse box, but the best way is to check your repair manual to find where it is located. Testing a 4 pin relay is often very straightforward. Remove the relay and give 12 volts to pin 30 and 85. Ground pin 86 and check if there is voltage coming out from pin 87.

What should I do if my car fan won’t turn on?

On modern vehicles, a bad sensor usually triggers the check engine light. Scan the computer for trouble codes, if necessary. If the fan fails to come on, first check for a fan blown fuse or triggered breaker. On older vehicle models, you may have a fusible link in the circuit.

How does an electric cooling fan work in a car?

However, some longitudinal (front to rear) mounted engines use the electric fan as well, but they usually have an engine-powered cooling fan. The electric cooling fan uses a direct current (DC) electric motor with a thermo switch, module or computer control to turn it on or off, depending on coolant temperature or AC operating condition.

Why does my AC fan not come on?

When the ac is of the radiator hoses both become same heat after a while and the overflow reservoir starts boiling over and the fan do not kick in. Any advise please. You might have an initial temperature sensor which causes the fan to come on when the temperature begins to rise; that sensor might be defective.

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