- Blown fuse: If the fuse that powers the air conditioning has blown, the air conditioner will not receive any power. Check the fuse box in your Kia's engine bay and replace the blown fuse if necessary.
- Faulty relay: The air conditioning relay is responsible for switching the power on and off to the air conditioning compressor. If the relay is faulty, the compressor will not receive any power and the air conditioner will not work. To check the AC relay on a Kia, remove the relay and shake it. If you hear anything rattling inside, it means that the relay is broken.
- Faulty pressure switch: The pressure switch is responsible for sensing the pressure of the refrigerant in the air conditioning system. If the pressure is too low, the switch will open and the air conditioner will not work. To test the pressure switch, disconnect the electrical connector from the switch and jump the terminals with a piece of wire. If the air conditioner starts working, it means that the pressure switch is faulty and needs to be replaced.
- Faulty compressor: If the air conditioning compressor is faulty, it will not be able to compress the refrigerant and the air conditioner will not work. To test the compressor, remove the serpentine belt from the engine and try to turn the compressor pulley by hand. If the pulley does not turn, the compressor is seized and needs to be replaced.
- Low refrigerant: If there is not enough refrigerant in the air conditioning system, the air conditioner will not work properly. You can check the refrigerant level by using a refrigerant pressure gauge. If the pressure is too low, add the required amount of refrigerant.
