Car AC Stopped Working Suddenly [Not Blowing Cold Air]

It’s frustrating if your car AC stopped working suddenly, especially in the middle of summer. What are the reasons why your car AC stopped blowing cold air?

6 common reasons why your car AC suddenly stopped working are as follows:

  1. Leaking Refrigerant
  2. Blocked or Clogged Condenser
  3. Broken Condenser
  4. Electrical Wiring Issues
  5. Malfunctioning Fan
  6. Malfunctioning Compressor

The car AC not blowing cold air is not limited to these problems, but they are the most common ones. Some of these problems can be diagnosed and fixed at home, and some will require a mechanic’s expertise.

Read on to learn more about why your car AC stopped blowing cold air all of a sudden and how to solve this issue.

Car AC Stopped Working Suddenly

When your car air-conditioning suddenly stops working, it’s usually due to a leak or issues with the compressor. Your AC may be blowing air, but it’s not cold.

The common problems are the following:

  1. Leaks
  2. Blocked Condenser
  3. Malfunctioning Condenser
  4. Electrical Issues
  5. Cooling Fan Problems
  6. An inferior Compressor

Here’s a more detailed explanation for the possible reasons why your car AC stopped blowing cold air all of a sudden:

1. Leaking Refrigerant

One of the most common reasons why your car AC stopped blowing cold air is a leaking refrigerant.

This problem is also one of the cases that are effortless to fix. You can buy a UV/AC detection leak kit and perform the task yourself easily. The detection kit uses dye, and it shows you exactly where the leak is.

A leak can be anywhere in the air-conditioning system. But they usually happen at the A/C unit connections of the hoses. When you spot an oily buildup on the hose, then that’s most probably where the leak is. When you spot where the leak is coming from, you can use a sealant to seal it up.

2. Blocked or Clogged Condenser

If your car AC suddenly stopped blowing cold air, then the condenser might be blocked or clogged.

Over time, your condenser will accumulate debris and may clog it. Your condenser works to cool the hot refrigerant, and when it is clogged, it can’t do that. If your AC is on at the highest setting and it still doesn’t blow cool air, check that both the condenser and the radiator function properly.

The condenser is located at the front of your car and is easy to spot. It will be easy to check visually if any debris is clogging the condenser. Remove anything that may be blocking it, and then check if your AC is working properly.

3. Broken Condenser

It may also be possible that your condenser is already totally broken. It may have been damaged from a puncture from sharp or rough debris. Check visually if you think you have a damaged condenser. You’ll need to replace the condenser if it is damaged.

4. Electrical Wiring Issues

If you have electrical issues with your car’s AC, it will be a little difficult to diagnose. You will need a mechanic for this, but you can start and inspect the wiring and see if anything is frayed or cut.

This includes checking the car’s relay. You can repair any damage by temporarily using electrical tape until you find a final fix.

5. Malfunctioning Fan

When your AC in car stopped working, you might want to check your fan.

Cooling fans are located either in front of or behind the radiator. They work to ensure proper airflow. You need to check if your cooling fan is properly functioning.

Look for cracks or any debris that may be hindering your fan from working properly. You’ll need a professional to check your fans because this will include checking fuses that may have blown.

6. Malfunctioning Compressor

If your AC stopped working in the car, then your compressor may be malfunctioning.

Your car’s compressor is vital in having your car’s AC run. It makes the refrigerant run through the system and generates cold air. Car compressors break when you don’t use your car for a long period of time.

To avoid this, you’ll need to run your AC on full blast every 2 weeks or so. Please turn it on the highest possible setting for about 20 minutes to help keep the compressor working well and extend its lifespan.

How to Diagnose Why Your Car AC Suddenly Stopped Working?

When the AC suddenly stops working, it can be a frustrating experience. Identifying where the problem started is key to having your AC up and running again.

Here’s how you can diagnose why your car AC suddenly stopped working:

1. Turn on the AC with the Car Running

ac stopped working car

When car AC not blowing cold air happens, try to diagnose this by turning your AC to ‘fresh air.’ Let the air blow out from the vents in the center of your dashboard. Let the air run at the highest speed for the fan.

2. Listen for Noises

When your AC is turned on, listen for noises. An unusual noise can be indicative of a problem with your compressor. If this is the case, get your compressor checked.

3. Feel the Air Coming Out

Feel the air coming out of your air vents. Check if the air coming out is cold, room temperature, or really hot. It may be blowing cold and then warm alternately too. You’ll need to tell your mechanic exactly what air your AC is blowing or if the car AC is not cold enough.

Also, note the air pressure of the air coming out. Pressure should be different when your AC is turned on at low and when it’s turned on at high. The pressure should increase as you turn it higher.

5. Check the Air Filter

One reason why your AC in car is not cold is that your filter is clogged.

Your air filter may be clogged with dust and dirt. You’ll usually be able to tell if it is dirty if you smell a dusty odor emitting from your AC. Replacing your air filter can be done quite easily and is inexpensive. Check your car manual for changing air filter instructions.

6. Check the Fuses

A car AC that stops working suddenly maybe because of a blown fuse. Cars have a fuse box, but it varies where they are located. Look at your manual and see where it is and check the fuses inside. Fuse boxes may be located in the trunk, hood, or driver’s foot area.

Again, if your car AC stopped working suddenly, then here are the possible reasons:

  1. Leaking Refrigerant
  2. Blocked or Clogged Condenser
  3. Broken Condenser
  4. Electrical Wiring Issues
  5. Malfunctioning Fan
  6. Malfunctioning Compressor

Other Reasons Why the Car AC Stopped Blowing Cold Air

When you’ve checked the 6 reasons above and still don’t know the problem, the problem is probably not common. So follow the steps below to further narrow down the cause of the faulty AC:

1. Examine Your AC Compressor and Clutch

Your AC has a refrigerant called Freon and is much needed to make it blow cool air. This Freon is circulated throughout the AC system by your AC compressor. 

Sometimes leaks happen in the seals of the compressor or in the compressor itself. Sometimes too, parts inside the compressor get worn out, causing a problem with your AC.

There is a part, the AC clutch, which is an engagement clutch that can fail and makes the compressor fully incapable of functioning.

2. Check If the Freon Is Low

Check if your Freon is low because if it is, there will be visible leaks. The leaks will appear green and oily.

3. Check the AC Orifice Tube

Check your AC orifice tube or expansion device. Depending on your car, you will have either one of the two. Both of them work to regulate the flow of Freon throughout your air conditioning unit.

Check to see if the air pressure is abnormally high or low, and if it is, the AC orifice tube or expansion device could be the culprit. Make sure your Freon levels are good and your fans are functioning correctly.

4. Check the AC Evaporator Core

The evaporator core is usually in the passenger compartment, under the instrument panel. This holds the refrigerant that has been cooled. The refrigerant basically absorbs heat and needs to be cooled. The AC evaporator core works as a freezer, cooling your refrigerant.

Wear and tear can make your AC evaporator malfunction or fail to work. Leaks can also occur. Check your drain tube, and if an oily or green substance can be seen, there is a leak.

These things need to be checked too. But the most common reasons why your car AC suddenly stops working are leaks, blocked condenser, malfunctioning condenser, electrical issues, cooling fan problems, or an inferior compressor.

How to Care for Your Car’s AC

Here are some tips on how to properly care for your car’s AC:

1. Always Clean Your Air Filter

Your air filter will accumulate dust and dirt, just like your AC unit at home. To make sure that your AC works at its best, do the following:

  • Clean the air filter at least once a month
  • Check your car user manual for instructions on how to remove the air filter
  • Clean with soap and water and then replace

2. Remove Bad Odors

Your AC will also be prone to emitting bad odors because of mildew and bad smell absorbed from the environment. Cars use defoggers to remove fog and moisture, which are actually heat-generating defrosters.

You will need to dry your evaporator now and then after using your AC for long periods of time to ensure it continues to run well.

3. Regularly Run Your AC

You may not use your AC for a while, especially in the dead of winter. This may cause the gas pressure to drop and make the compressor malfunction. To keep your AC running smoothly, run your AC at least once a week.

Turn it to the highest setting and let it run for about 20 minutes. This should also be done with the defrost feature so that it will run smoothly.

4. Get a Complete Checkup for Your Entire AC System Annually

car ac stopped blowing cold air

Getting an AC annual check-up is sort of like getting an annual physical check-up. You think you don’t need it, but you do. Even if you think everything is running well, things will need to be checked to catch problems early.

An overall AC system check-up will consist of checking 3 major things. These are the evaporator, compressor, and condenser. If your car is over 5 years old, these annual check-ups become more important because the AC system becomes more prone to breakdowns.

Conclusion – Car AC Stopped Blowing Cold Air All of a Sudden

When your car AC suddenly stops working, it’s usually because of one of the following reasons:

  1. Leaking Refrigerant
  2. A Blocked or Clogged Condenser
  3. Broken Condenser
  4. Electrical Wiring Issues
  5. Malfunctioning Fan
  6. Malfunctioning Compressor

The above reasons are the most common ones, but they are not limited to that. If your car’s AC is not blowing cold air, address problems immediately so that they do not get any worse.

During the hot summer months, you’ll need your AC to be working in tip-top condition because driving in a hot, humid car is really uncomfortable. It is best to keep it serviced just before summer. Follow the tips we gave above on how to care for your AC so that it runs all the time smoothly.