Q: When I turn ac on it overheats

asked by on

I have a 2008 ford focus two door coupe. When its a hot day out, I have my ac on full blast, when im sitting at a light my air starts to get hot, then my car starts to overheat. But when I start driving again the air cools down and the temperature gauge goes back to the middle white line. It will do that a few times before it starts just overheating. When its more towards night time and its not so hot out, my car works just fine, I can have the ac on and it doesnt give me any trouble. Please help. Ive tried the thermostat, the water pump the radiator hose. Im starting to lose hope.

My car has 4400 miles.
My car has an automatic transmission.

Your car is equipped with an electric radiator fan. It should come on when the engine reaches a certain temperature. It should also come on immediately when you turn the air conditioning on. While on the move, the fan does not need to run but when driving at low speeds or stopped, it should be running.

It sounds like your fan is not coming on at all. That can be caused by a number of things:

  • bad coolant temperature sensor
  • bad fan relay
  • bad fan motor
  • bad ECU (unlikely)

You may want to have a professional diagnose your AC system issue properly, rather than just start changing parts because that can get expensive.

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
  1. Home
  2. Questions
  3. When I turn ac on it overheats

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

Q: Only getting luke warm heat out my vents

Hello. The heater is a part of the vehicle's cooling system and uses the same fluid. The first thing I would do is check to make sure that the system is properly filled and bled. If any air gets trapped...

Q: My 1998 Buick Park Avenue only runs hot when in traffic or just idling. What's the cause of it running hot?

Either the cooling fans on the radiator are not working properly or the radiator is plugged up to where there is a restriction when the engine's water pump is running at a slow speed. If you suspect that the radiator...

Q: I have a 08 ford focus, its super cold and it tries to turn over but ultimately won't, the battery is giving me 12.3 volts.

When the weather gets cold, I replace a lot of batteries. If your battery is marginal, it will work just fine until the temperature drops, then it won't have enough reserve to do the trick.Testing it with a voltmeter won't...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...