If your car's air conditioning/heating system does not seem to be working properly, there could be a few different reasons. Though air conditioning systems are not the most complex part of an automobile, they are not simple to diagnose and repair. You can check the car's compressor to see if it is working properly. However, you should have an experienced mechanic replace this part, as it involves working with high-pressure systems.
Turn your car on and roll down the windows. Turn off the radio and air conditioning. Allow the car to run until it reaches its normal driving temperature then turn the climate control knobs on to "Cool." Listen for the compressor to kick on. If you do not hear it, turn the car off and open the hood. Let the engine cool.
Inspect the compressor's electrical wiring for disconnections, breaks or burn marks. If any electrical wires are unplugged, reconnect them. If you see breaks or burn marks in the wiring, disconnect the wires and take the compressor to a trained technician for repair. If no breaks or burn marks are present, open the fuse box on the driver's side. Read your owner's manual or the diagram on the fuse door to find the fuses corresponding to the air conditioner. Replace any blown fuses.
Attach a freon recharging kit to the air conditioning system. Follow the manufacturer's instructions for how to hook up the recharging kit to the car. Add UV dye to the recharging lines. Start your car and turn the air conditioner on its coolest setting. Once the UV dye has entered the air conditioning system, turn your car off and pull it into a garage.
Turn off the garage lights and block windows with cardboard to create a dark environment. Shine a black light under the hood and look for a green fluid glowing under the black light around the air compressor. If you see green fluid glowing, this means the compressor is leaking. Take the car to an experienced mechanic to have the compressor replaced.
