Q: My radiator fan only turns on when my AC turns on.

asked by on June 14, 2016

My car has been over heating when my AC is off.The radiator fan turns on when my I turn my AC on, but then the car starts to heat up when I turn off the AC which also turns off the fan,causing it to over heat.

My car has 180502 miles.
My car has a manual transmission.

Car is overheating Inspection $94.99 - $114.99 Get a Quote

Hello there, a couple of different items can cause the fan to not work like this. The most likely culprits are a thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay, or a wiring issue. If the vehicle overheats, care should be taken when driving to prevent further damage by overheating. When the vehicle has the AC on, the engine needs extra help cooling so the ECU commands the fan to be on any time the AC is on. A qualified technician, such as one from YourMechanic, will be able to diagnose your overheating problem and perform any repairs required.

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Does my car require synthetic engine oil or any oil additives?
Take a look at any auto parts store today and you’ll see a ton of different options when it comes to engine oil. There’s conventional oil, synthetic oil, and even conventional/synthetic blends. Any oil can be used in your Accord,...
Car sputtering while idling.
There could be a number of issues that can cause this concern. If the issue only occurs after the engine has warmed up. A problem in the electronic throttle control actuator either in the motor or one of the sensors...
Code B11E5
Hi there. This fault code indicates a failure in the circuit for the left HVAC damper position sensor. This fault can be connected to the operation of the left temperature blend door. Have an experienced technician inspect the electrical components...
Why is my ABS light on-on the dash?
The ABS system turns on the light when it sees a fault in one of its sensors or output components. In order to properly diagnose the system, you will need to have the ABS system scanned to see if there...
when shifting gears release clutch feel like it's still engaged
This is a symptom of a slipping clutch disc. You should have a mechanic verify the clutch linkage is not binding and quote the replacement clutch.
At what mileage should I get my timing chain replaced?
Your Lexus IS250 uses a timing chain rather than a timing belt. Fortunately, the timing chain does not require regular maintenance like the belts typically do. Just be sure to perform regular services on your car such as oil changes...
Replaced cv axle with non oem still getting clicking.
Hello. The play where the axle connects to the differential can be a bad bearing in the differential or more commonly the inner joint of the axle. Most of the time when this occurs it is because of a defective...
Loss of power when accelerating - 2012 Chevrolet Aveo LT
Hello. Be sure to never open the cooling system while the engine is hot. The difference in pressure between the inside of the system and atmospheric pressure will always cause the hot coolant to boil out and may cause harm....
Jeep Grand Cherokee loses power when accelerating breaks up like the fuel is deprived.
Hello and thanks for writing in. I believe you are headed in the right direction. I would suggest checking the MAP sensor (https://www.yourmechanic.com/services/manifold-absolute-pressure-sensor-map-sensor-replacement) as well as fuel pressure to be sure that all fuel injectors (https://www.yourmechanic.com/services/fuel-injector-replacement) are firing properly and...

Related articles

Do All A/C Systems Use Refrigerant?
All air conditioning systems use refrigerant. Refrigerant dissipates heat in the air conditioning system to keep your car cool in hot weather.
Symptoms of a Bad or Failing Blower Motor Switch
If your blower motor switch only works on certain settings, gets stuck, or has a broken knob, you may need to replace your blower motor switch.
How Long Does a Refrigerant Pressure Sensor (Switch) Last?
Your Your car’s air conditioning system helps keep you and your passengers cool and comfortable during hot weather. It also plays a role in operating the front defroster. In order to operate properly, the system needs a refrigerant – just...