Car Air Conditioner

Car Air Conditioner Maintenance: 4 Troubleshooting Tips

It’s hot out there! Soon, you’ll be slipping behind the wheel of your car, starting the ignition and powering on the air conditioner. But what do you do if the car air conditioner is blowing hot air or, worse yet, not functioning at all? Here are four tips to help you forego the perspiration and get some inspiration to fix your air conditioning:

Air conditioner1. Examine the Cabin Air Filter

Your car’s cabin has an air filter, which expedites the flow of air from the air conditioning system under the hood and into your vehicle’s interior. That filter is located either inside your glove box, under the dashboard or under the hood. Wherever it may be, locate it and pull it out. You will know that it is clogged if it is blackened and filled with debris. Replacing it may be all it takes to resolve your car air conditioner problem.

2. Raise the Hood and Check the Condenser

Under the hood, immediately in front of the radiator, sits another part prone to clogging: the condenser. Fortunately, you don’t have to remove the condenser to clean it and free up air flow. Instead, simply put a garden hose on a medium to high setting and direct the water flow through the grille’s louvers. The lower portion of the grille is an especially important target, as that is where contaminants like road salt will collect.

3. Check the Cooling Fan

What do you do if there is no air coming out of the vents at all? Today’s cars are usually equipped with under-the-hood electric cooling fans so when the air conditioner is on, the cooling fan is working. If it isn’t working, then either the relay, temperature sensor, control module or fan motor has malfunctioned. In most cases, the relay is to blame for shutting down your air conditioner. Visible signs of corrosion or burnt wiring are a sure indicator that the relay should be replaced.

4. Examine the Compressor

Another critical component in the car air conditioner system is the compressor. The compressor is tasked with handling low-temperature refrigerant gas and compressing it into a high-pressure, high-temperature gas. When the compressor is working, it sends refrigerant to the condenser. The compressor should be turning if the serpentine belt is turning; if the belt is not turning, it may need to be replaced. If it is turning, then the clutch wire or compressor piston may have broken.

Other possible problems could be a bad thermostat, bad clutch oil or low refrigerant levels, which can cause the compressor to shut down. Unless you have the tools and the expertise required to address these issues, your compressor problems should likely be left to the professionals.

Troubleshooting Considerations

Although some air conditioner problems can be resolved using common hand tools, more complex problems may require air conditioning testing, scanning and specialty tools, something not every weekend mechanic owns. When in doubt, take your car to a mechanic — a wrong move could do further damage to the air conditioning system.

Check out all the air conditioning system parts available on NAPA Online or trust one of our 16,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on car air conditioner repairs, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Image courtesy of Flickr

about author

Matthew C. Keegan

Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.

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  • Jeff Madison

    April 6, 2016 at 9:27 PM


    I appreciate your tip on checking various parts of the car when your AC is having trouble. It seems that checking things like the cooling fan and compressor would be helpful in finding out if there is something is wrong with your car. I would imagine that if you do end up having any complicated issues, however, you would probably want to take your car to a service shop instead of just trying to fix it yourself.

  • Sarah Smith

    May 12, 2016 at 4:04 PM


    Thanks for the advice about troubleshooting a car’s AC unit. My car has been having problems for a while and I didn’t know what was wrong with it. Now I know that I need a new air compressor and then my AC unit will work fine.


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