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: Should I buy a new or used air conditioner compressor for my car?

Buying a used air conditioning compressor could lead to more problems. You could easily end up having to do the job twice and a new compressor is not so expensive that I would take that chance. The good news is...

Q: How do I use the maximum air conditioning?

The maximum air conditioning feature cools your vehicle at an even faster rate than the normal air conditioning. To turn on the maximum air conditioning, press the Max A/C button.

Q: I replaced ignition tumbler and put it in wrong, now I can't get it out.

I never installed one or knew it would go in upside down. However, I would suspect you would have to drill the tumbler out like I would have to do if I did not have a key. Did you try...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.