Air conditioning facilitates the removal of heat from inside the vehicle. There are a number of reasons why a car air conditioner stops working. By thoroughly checking the system you will be able to pinpoint the area of the malfunction. Once you have identified the problem it will be much easier to correct.
Check the serpentine belt. This belt is used to supply the power that rotates the compressor. If the belt is not working then there is nothing to drive the compressor.
Identify if there is clutch engagement with the compressor. Turn the air conditioner to the lowest and coldest settings. With the car idling, look at the clutch at the front of the compressor. If it is turning then it is working and active.
Inspect the fuses. Using a test light, check under the dashboard panel and hood for bad fuses. Replace any fuses that are not working as indicated by the test light.
Check for leaks. Use a leak detector to identify if refrigerant is leaking out of the car. If the leak detector indicates low pressure then you may have a leak. Check your owner's manual for recommended pressure for your system.
Inspect the vents. If the vents inside your car are not working properly you may not be getting the cool air that you should. With the car on, set the blower to low and the temperature to warm. With your ear close to one of the vents, switch the temperature from warm to cold. You should hear noise from inside the vent as the door inside the heater box switches from the closed to open position.
