At what temperature should my cooling fan come on?

Asked By: Prudence O toole | Last Updated: 18th February, 2020
Category: home and garden indoor environmental quality
4.7/5 (274 Views . 42 Votes)
To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches about 200 to 230 degrees. If the fan does not come on, something in the control circuit is defective.

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Keeping this in view, what temp should car fan kick in?

about 200 degrees Fahrenheit

Beside above, should cooling fan come on when AC is on? If the coolant level in the radiator is low, that can cause overheating inside the engine without the radiator fans running. Check that first, refill if necessary, burp air pockets from the cooling system. Both radiator fans should always run when the AC compressor is engaged.

Accordingly, how do I know if my cooling fan is bad?

Usually a bad or failing cooling fan motor will display a few symptoms that can alert the driver of a potential problem that should be serviced.

  1. Cooling fans do not come on. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on.
  2. Vehicle overheating.
  3. Blown fuse.

How long does a radiator fan take to turn on?

15-20 minutes

26 Related Question Answers Found

Where is the cooling fan sensor?

The cooling fan relay is normally located in either the underhood fuse and relay center or mounted to the electric fan assembly behind the radiator.

Does radiator fan affect AC?

Yes, a broken radiator fan can cause the air conditiong to stop working. The AC system depends upon being able to dissipate heat into the engine coolant. You really need to have the fan replaced, or at least, have a diagnostic check to see what is causing the fan to stop working.

What coolant temperature is too hot?

Too Hot. The acceptable range for an engine to run at sits between 195 degrees and 220 degrees Fahrenheit. This assumes a person is running a 50/50 mix of antifreeze and water.

Can one radiator fan drive?

Yes, you can drive your car without a radiator fan, but you never should. Your vehicle's cooling system is crucial to its performance, and every time your engine overheats, you cause damage.

What are the signs of a bad temperature sensor?


Common symptoms of a bad engine coolant sensors are overheating, hard starting conditions, poor idle, check engine light ON and the electric fans do not work properly. The easiest way is to read the trouble code memory and check the value from the sensor, to make sure it's a possible value.

Why does my radiator fan come on when I start my car?

If the fan comes on, you may have a bad temperature sensor or gauge. 2. A cooling fan temperature switch (or sensor, in some vehicles) can also get stuck, which may cause the fan to run continuously any time you turn the ignition key on or start the engine.

Does the coolant temp sensor control the fan?

The sensor works by measuring the temperature that's being given off by the thermostat and/or the coolant itself. The temperature is then sent to the on-board control system. As the control system receives the temperature from the CTS, it may trigger the cooling fan to either shut off or turn on.

How long does it take for a car to cool down after overheating?

How long will it take my car to cool down after overheating? If your car's overheating, pull over, switch off the engine and wait for at least 30 minutes for the engine to cool down. To be on the safe side, it's preferable to wait an hour or two to fully let your engine cool.

How do you test an engine cooling fan?

How to check your car's cooling fan
  1. Set the car heater to cold.
  2. Run the car until the engine reaches normal temperature.
  3. Watch your temperature gauge – don't allow the car to overheat.
  4. The cooling fan should cut in automatically and the temperature gauge drop back to normal.

Does radiator fan run all the time?


An electric fan SHOULD NOT run all the time. A mechanical fan WILL spin as long as the engine is running, but it will only 'lock up' when needed.

How do I test my electric radiator fan?

How to Check a Radiator Fan
  1. Determine whether your radiator fan is manual or electric.
  2. To check an electric radiator fan, start the car and let it get up to the temperature where the fan normally kicks on.
  3. Use the volt meter to test if there is power to the wires.
  4. Normal voltage for a radiator fan is around 12 volts.

How much does it cost to replace a cooling fan?

The average cost for cooling fan replacement is $240 to $610 depending on the make, model, and style of cooling fan used.

How much is a cooling fan relay?

So, when the cooling fan relay stops working, the coolant can get too hot, and the car can overheat. To get your cooling fan relay replaced, you will pay, on average, $80-$160, depending on the type of car you have and the mechanic's fees. The labor should cost around $70, while parts should run you $10-$50.

How much does it cost to fix radiator fan?

The average cost for a radiator fan motor replacement is between $634 and $789. Labor costs are estimated between $102 and $130 while parts are priced between $532 and $659. Estimate does not include taxes and fees.

Why is the fan on my car not working?


If the sensor isn't working, your fan won't come on because it won't know that the temperature is hot enough to require activation, which can frequently lead to overheating. The sensor is usually located in the car thermostat cover. To check it, disconnect the wires from the sensor and touch them together.

How do you test a coolant temperature sensor?

Connect the black lead of the meter to the body of the cold sensor and the red to the terminal. You should have a reading of approximately 2000 ohms. Check the warm sensor in your engine. You should see a much lower reading on the ohm meter.

What causes cooling fan to stay on?

Depending on the wiring setup of the vehicle, this may cause them to stay on even when the vehicle is off, which will drain the battery. The cooling fan relay essentially functions as the switch for the engine's cooling fans, and is therefore an important electrical component of the vehicle's cooling system.