Car AC Not Working? Here's 5 Ways to Diagnose the Problem

Air conditioning is one of those things that’s easy to take for granted — until you don’t have it. When it’s the middle of summer and the temperature outside is rising, the last thing you want is to be stuck in a car that’s blowing hot air out of the vents … or in a car with an air conditioner that's not blowing at all.

Even though Ohio is known for its moderate summer temperatures of about 80 degrees, the high levels of humidity can make it feel hotter and stickier. Being in a car without air conditioning in hot weather isn’t just annoying; it can also be dangerous, since cars heat up quickly. This puts you at risk for dehydration and even heat stroke.

It’s even more dangerous for children, the elderly and people with compromised health, so making sure your air conditioning is in good working condition is definitely something you want to make a priority this summer. That means if you’re hitting the road this summer, you’ll probably want to have your mechanic give it a quick checkup before you go.

Why Your Air Conditioning Isn’t Working

Like most things under the hood, air conditioners can stop working for a number of different reasons. Knowing what to look for can help you troubleshoot why your car A/C is not working and let you know what steps you need to take next. Let’s look at five common reasons your car A/C might have stopped working.

No. 1: Your Car Has a Refrigerant Leak

This is one of the most common causes of car A/Cs not working. Leaks can originate from a number of different places; it could be the result of rubber seals and hoses breaking down over time, and that allows the refrigerant, Freon, to escape. The bigger danger when this happens goes beyond not having cool air in your car, but those weak spots can also allow moisture to get inside your car’s cooling system and mix with the refrigerant. When moisture and Freon mix together, they create a dangerous acidic combination that can corrode your A/C system and cause permanent damage.

As with any type of leak, you want to get this fixed quickly so it doesn’t continue causing problems for your car.

No. 2: Your Cooling Fans Are Broken

Just like you need blowers to push the air conditioning through the vents in your home, your car uses cooling fans to move the refrigerated air into your vehicle’s cabin. When there’s a problem with the fans, you won’t feel any air coming out of the vents.

Cooling fans can stop working properly for a number of different reasons; they might have blown fuses, an electrical short, or could have been cracked by debris from the road. Fortunately, this is fairly simple to fix; your mechanic should be able to replace it quickly and get you back on the road.

No. 3: There’s a Problem With the Compressor

Your air conditioning relies on a compressor to keep the air moving, but if the compressor isn’t working properly, that refrigerant isn’t going to move around. One of the main reasons a compressor goes bad is from not being used for long periods of time, and the long cool seasons of fall and winter means that many Ohioans don’t run their air conditioning for several months.

A compressor can also have problems if the clutch on the compressor gets stuck. If it gets stuck in the “on” position it will make your air conditioning run continuously, and if it’s stuck in the “off” position it will keep the compressor from engaging. You’ll need to have your mechanic look at what is causing the problem with your compressor.

No. 4: There’s Something Wrong With Your Condenser

The condenser plays an important role; it takes the humid air in the air compressor and depressurizes, cools and liquefies that air. In simpler terms, it helps turn the air cool. When your air conditioning isn’t cooling as much, it could be a sign of a failing condenser.

No. 5: You Have an Electrical Problem

There are several things that can cause electrical problems for your car’s air conditioning. These can include failed switches, a blown fuse, a problem with the control module or something else. Fuses can short out and make the A/C stop working or a loose connection can create an electrical short that is easily fixed.

While electrical issues in the air conditioning system are often easy to fix, they need to be addressed immediately, since they can cause acid buildup. Acid buildup can cause serious damage to your vehicle and can even lead to needing to replace the entire air conditioning system. Staying on top of problems will keep this from happening.

Plan Ahead to Stay Cool This Summer

Unlike many of the systems in today’s cars, there aren’t any warning lights that will alert you to problems with your air conditioning system. Since you don’t want to wait until a problem occurs, and all too often those problems pop up at the most inconvenient times, it’s a good idea to take your car in before the hot weather arrives and make sure that the hoses and fans are in good working order, no leaks are evident and your refrigerant levels are good. (This can also be done as part of your spring tune-up.)

Taking the time to have your air conditioning checked before summer gets underway, or as soon as you notice a problem, can save you a lot of grief, time and money. And it will also help you keep your cool all summer long.

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