Auto Air Conditioning Repair

hand holding car AC coolant device
  • 1-6 hours
  • Advanced
  • 1,200-1,500
What You'll Need
Auto mechanic tool set
Fuse wire
Voltage tester
Duster cloth
Fluorescent dye
Pressure gauge
What You'll Need
Auto mechanic tool set
Fuse wire
Voltage tester
Duster cloth
Fluorescent dye
Pressure gauge

An auto air conditioning system is an air conditioning system that makes our travel cozy and comfortable. Basic knowledge of this air conditioner is essential to manage the repairs of this system.

If, for some unknown reason, the air conditioning isn't working, try some of the methods given below to troubleshoot the problems yourself. Many of the possible causes of a faulty auto air conditioner system are actually quite easy to fix yourself.

Age of Vehicle

car AC device

Before you begin any repairs to your vehicle, make sure to check if it is still under warranty. If it is a new car, chances are it is. Making certain repairs yourself can actually void the warranty.

So if your car is still under warranty, it may be worth it to bring it into the dealer and have the company be the one to address the air conditioner issue.

If it is an older car, however, bringing it into the dealer can cost hundreds if not thousands of dollars. It is possible that you will have to go this route, but it is worth it to first try figuring out what the problem is and fixing it yourself, and bringing it to the pros as a last resort.

If your car is incredibly old, think vintage level, you may need to take it to an expert in that type of vehicle as the average mechanic may not have parts available for your specific vehicle or the knowledge necessary to fix it without risking causing other issues.

Check for Any Leaks

car coolant leak

A leak can be a common culprit of a faulty auto air conditioner system. Thankfully, leaks are fairly easy to detect.

To start, walk around your vehicle and take note of any leaks. If you do not find anything, you can take a slightly more difficult approach.

To do so, grab some fluorescent dye. You may want to ask your local auto repair shop for one that is easy to spot but more environmentally friendly. Once you have the fluorescent dye, add it to your auto air conditioner and then turn on the air conditioner system.

Do not be impatient here. It may take a few minutes for this to work. Leave the auto air conditioner on for a few minutes and then check the coils. If there is a leak, you will see fluorescent dye on the coils.

If you see fluorescent dye on the coils, you know a leak is to blame for the faulty air conditioner system. From here, you can either fix the issue yourself or bring your vehicle into a mechanic or other professional.

Fixing the leak could cost anywhere from $100 to $800, depending on the cause of the leak. If the leak was caused by a crack hose, for example, it will need to be replaced, which can cost a lot of money. If it is simply some debris you need to flush from that system, it is a much easier fix.

Once you or a trained professional are finished fixing the leak, you can wipe the fluorescent dye off the coils on your system. Do not forget to do this as it can leave the coils permanently dyed another color if you wait too long to clean them.

Not cleaning it also will make it difficult to detect leaks in the future as your coils will already have the color of the fluorescent dye.

Check the Level of Refrigerant

hands holding car coolant device

If, when using fluorescent dye, you discovered that there are no leaks in your air conditioner system, it is time to check the level of refrigerant in your car. A low amount of refrigerant is another common cause of an air conditioner system not running properly.

In many vehicles, you will find that Freon is being used as the refrigerant to keep things cool. Freon is a combination of gas and liquid that is compressed and circulated to cool the air.

Before you look at the Freon, however, read up on local regulations as many jurisdictions do not allow non-professionals to do anything with Freon themselves.

To check the level and the pressure of the Freon in your vehicle, you must attach the pressure gauge to the compressor hose, start the AC system and take the readings. A pressure gauge is a very cheap device you can buy online or at any store that sells auto equipment.

If any one of the measures is below normal, then the Freon 134A has to be refilled. Again, read up on local regulations before doing this yourself.

In many areas, due to environmental issues and strict federal laws governing them, only a qualified technician can refill Freon. Thus, it is recommended to get the optimum pressure of Freon restored locally by a qualified technician.

Make sure to look around for someone who is properly qualified to refill Freon in a vehicle.

Look for a Clogged Condenser

If neither of the above issues is applicable, it is time to look at your auto air conditioner's condenser and check for the status of the condenser. The air conditioning condenser is a radiator that is located between the car's grille and its engine cooling radiator. When it is not working properly, it can become quite loud.

If it is clogged, then the cooling fan closer to it cannot turn on. If the fan is not on, your vehicle will not be cool.

If you see dust, debris, or anything else in the condenser, remove it. This is much simpler than it sounds. All you really need to do is clean the condenser with a duster to remove any particles that have gotten inside of the condenser.

Once any unwanted debris has been removed, turn on the air conditioner. It may take a few minutes to start back up but should work fine.

This is a really easy problem to solve and one that under no means do you need to take your car into a professional for. Doing so will cost you hundreds of dollars and a lot of time when all you really need to do is clean out the condenser.

If the air conditioner condenser needs to be replaced, however, it will cost more and isn't as easy to do. It can cost $200 to $1,000 to replace the air conditioner condenser in your car depending on its make and model and whether you take on the job yourself or leave it to the pros. The labor itself will cost a few hundred dollars.

Understand Compressor Problems

car AC compressor

The compressor is the heart of an auto air conditioning system. That's why issues with the compressor can wreak havoc on your auto air conditioning system, as in most cases, problems with compressors result in an inefficient auto air conditioner.

The air conditioner compressor is located at the front of the engine of your vehicle. This is where the other belt-driven accessories are located as well.

If there is an issue with it, you may hear loud noises when you run the air conditioner. You may also notice hot air instead of cold air coming out of your air conditioner system when you attempt to use it.

A compressor issue can also result in fluid leaks and in some cases a stuck clutch which can be quite dangerous when you are driving.

    To identify the problem, start the car. Once it has been on for a few minutes, turn on the air conditioner. Do not do so before your car warms up or you may think there is an issue with the air conditioner even though the real issue is impatience.

    After a few minutes, it is time to turn on the air conditioner. Once you have turned on your car's air conditioner, locate the compressor and check if it is running. The compressor is the part of the air conditioner that produces a humming noise.

    If it is not working, then the possible reasons could be a blown fuse, broken wires, switch problems, or a low level of refrigerants. Check for any of these conditions, fix it, and then re-check the compressor again.

    If you do not hear a humming noise associated with a compressor, but can't figure out what the issue is, it may be time to bring your car in for a professional to look at.

    Replacing an air conditioner compress usually costs around $1,000 depending on your car's make and model, who is doing the repair, and where you live. The labor will only cost a few hundred dollars as this is a fairly easy and frequently done repair, but the part itself will cost a pretty penny.

    If your car is still under warranty, though, this repair will likely be covered.

    Fan Belt

    fan belt in car engine

    An issue with a fan belt can also prevent a car's auto air conditioner from working properly.

    The belt of the fan can be found attached to the compressor and in front of the car's radiator. If it is not in its proper place, damaged, or not working for another reason, it can cause your auto air conditioner to stop running properly.

    Fixing it, however, is fairly easy. It could be a matter of replacing it altogether, removing some debris, or bending it back into place.

    It's also one of the cheaper replacements out there. In many instances, it will cost under $200. The belt itself is generally under $100, while the remaining money will go toward labor unless you chose to make the replacement yourself. Either way, it's a fairly cheap and straightforward task.

    Bad Wiring

    Another possible reason your auto air conditioner may not be working properly is simply bad wiring in your vehicle.

    Air conditioner compressors have a wire leading from them to the electric clutch. If this wiring is damaged, it can affect the way the auto air conditioner unit runs in your car.

    To check and fix this potential issue, start by unplugging the connector in that wire and connect the wire to the positive pole of the car battery.

    If you do not hear a ‘cluck’ sound when you connect the wire to the positive pole of the car battery, then you have identified the issue.

    If, however, you hear a ‘cluck’ sound when you connect the two, then the clutch is fine, and other wires and fuses have to be checked instead as one of them is likely causing the issue.

    If all of the wires you check are fine and still the air conditioner system is not working, then the electric clutch may be bad and needs to be replaced. This is a job you may want to take your car into the mechanic for as it can be quite difficult for someone who doesn't know much about cars to do.

    If All Else Fails

    In case these methods fail to rectify the problem, it is time to take your car to the mechanic. This will cost more, but if you live somewhere warm and are in the car a lot, it may be worth it to have the air conditioner fixed.

    If your car is old, you live in a more moderate climate, or you are thinking of selling your car, the cost of diagnosing the issue and fixing the air conditioner may not be worth it.

    Before bringing your car in, look online to find a mechanic or body shop with good reviews that's well versed in air conditioner repair and understands your vehicle's make and model.

    Dealers are generally more expensive than auto repair shops but are more likely to have the parts you need on hand and knowledge of your specific vehicle.

    If you have an uncommon make or model, it may be the way to go, especially if you need your automobile's air conditioner fixed quickly, since they may have the parts on hand and won't have to slow things down by ordering them or know their way around your specific type of car already.