Car will overheat if I don't have the fan on. When fan i...

Q: Car will overheat if I don't have the fan on. When fan is off it doesn't come on to release heat from engine. So the fan is always on.

asked by on March 15, 2017

So when i drive my car i have to have the fan constantly on. If not it will tend to overheat. And every time i check the fluids the reservoir tank for the coolant always seem to be full or seems like overflowing. I noticed that when the fan is off it doesn't usually come on automatically to release heat from the car like its supposed to thats when the car overheats. Only when i have the fan on med or high fan it goes back to normal. There is new sensor new thermostat and new radiator. What else could be the problem to this?

My car has 133000 miles.
My car has an automatic transmission.

Check the wiring to the coolant temperature sensor and see if there is power to the sensor switch. If there is no power, then check the cooling fan relay and see if its clicking on. If there is no clicking motion, then remove the relay and check for power to the relay. If there is power to the relay, then the cooling fan relay needs replaced. If there is no power to the relay, then check the fuse. If the fuse is burned, replace the fuse. If the fuse is good, then check power from the fuse to the main circuit on the fuse box. If there is no power, then the fuse box needs replaced. If the fan comes on with the air conditioning system switch turned on, that is because the switch overrides the cooling switch to make the condenser cool down to make the air conditioning system work properly.

If you need further assistance with your cooling fans not coming on when the engine gets hot, then seek out a professional, such as one from Your Mechanic, to help you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Hear noise on driver's side wheel when turning right

The first clicking sound is likely coming from a faulty CV axle. This clicking sound is made by a faulty joint within the cv axle. I would first recommend having a suspension and brakes inspection performed by a qualified professional....

Speedometer going on and off

From the symptoms you describe, it would appear that the problem you are experiencing is indeed electrical in nature. As electrical problems are often times difficult to diagnose, I would recommend having a professional technician, such as one from YourMechanic,...

Driver's side airbag not working

This question would require more information. I would need to know what indication is telling you the drivers air bag is not working? The vehicle has an Air Bag Light on the dash that comes on if a fault is...

Related articles

How to Replace an Anti-Lock Brake Pressure Switch on Most Modern Cars
Anti-lock brake systems (ABS) have a pressure switch that fails if the the light appears on your dashboard or there is wheel locking during braking.
How to Replace a Cooling Fan Resistor
The cooling fan may not work at all speeds if the resistor is broken. If the engine overheats or the fan never turns off, the resistor may be faulty.
The Top 5 Selling Cars in Arizona in 2012
Depending Depending on where you live in Arizona, the weather is either arid or there may be periods of heavy snow – such as in the mountain areas. The vehicles that have been popular in previous years for the area,...