AC Not Blowing Cold Air in Car – Fix the Top 5 Causes

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We often take the air conditioning for granted until it stops working. A barrage of heat waves has plagued the US this summer of 2021. And more above-average temperatures are on the way affecting more of the country than those before it.

Hence, you don’t want to get stuck in the middle of summer with a malfunctioning air conditioner. In this article, we are going to discuss the problem – AC not blowing cold air in car.

It is not just uncomfortable but dangerous as well. Since the car could get hot very quickly, it can cause dehydration and even heat stroke. That is why it is crucial to ensure the AC system is properly working during summer.

Reasons why your AC is not blowing cold air and how to fix them

Like most parts and components of your car, the car air conditioner can stop blowing cold air for many different reasons. If you know what to look for, you can easily narrow down the cause and troubleshoot it. The most common cause why you’re AC is not blowing cold air is a leak in the system. The leak can eventually lead to depletion of the refrigerant.

1. There is a leak in your AC system

To blow cold air, the air conditioning system needs a refrigerant – a chemical called Freon. The issue of AC not blowing cold air in car is most likely due to a leak. A refrigerant leak can occur at any point in the AC process – evaporator, condenser, or hose – making it difficult to pinpoint the exact location.
Here are the signs of freon leak:

1. There is a distinct click whenever you turn on the AC

2. AC turns on and off cycling

3. There is a hissing sound in the AC system when the engine is off

4. There is oil residue in the pipe fittings

Another reason why it is hard to find is that freon instantly evaporates once exposed to air. AC
Here are the methods to detect leaks in the AC system:

1. Through the use of dye and UV lamp – inject dye into the AC system. It will be visible under UV light, making it easier to detect leaks.

2. Using detector – You can buy an AC leak detector for around $35 on Amazon. The device has a sniffier where it pulls a small amount of air to find traces of the refrigerant

3. Checking the pressure in the circuit – You can do this by using a manifold gauge set.

Here is a Youtube video on how to use dye and UV lamp kit to detect AC leaks:

How to fix it?

car ac not blowing cold air in car

You can use an AC leak sealer if you found some small/pinhole leaks. You can buy these products for less than $50. So how does it work? An AC leak sealer comes in a compressed can with a nozzle. The sealer remains in liquid form until it comes into contact with the refrigerant on the leak point, where it becomes a hard sealer.

This quick fix is only advisable for minor leaks. It is not advisable for leaks around the O-rings or shafts. If not used properly, they can also cause issues to the AC system, reducing its performance.

The sealer may also clog the AC components leading to serious problems and expensive repair costs. Make sure to research first and read the manual before using this product.

2. AC needs freon recharge

Although it is unlikely, over the years, your AC could lose its refrigerant slowly, which is why the difference is barely noticeable. This is not because of a leak but rather common even in top-quality AC systems.

Furthermore, you may not realize that the AC cool temperature is one or two degrees higher than it should be. As soon as you notice that you have the AC not blowing cold air in car issue, your car may be already low on freon.

How to fix it?

It is best to have a certified technician or mechanic recharge your refrigerant. Here’s why:

3. AC condenser is blocked

The condenser transforms the refrigerant from its gaseous state into liquid by removing heat. It uses the airflow coming through the front of your car while you are driving. Sometimes, the condenser gets blocked by debris from the road. When this happens, the AC will not blow cold air into your vents.

How to fix it?

You can found the condenser in front of your car, so you can inspect it visually for any blockage. You can solve the problem by simply removing any blockage from the condenser. Make sure you have technical skills in dismantling and cleaning the condenser properly.

4. AC compressor failure

The compressor powers the AC system of your car. It pressurizes the refrigerant before reaching the condenser. Consequently, if the compressor is faulty, the AC system will not operate optimally, because it doesn’t have enough pressure to send it to the condenser.

The most common reason for a faulty compressor is that it hasn’t been used for a long time. The long-dormant period may shock the system once you used it again.

Looking for symptoms of a bad AC compressor is not difficult per se. If you experience the following signs, you may have a faulty compressor:

1. Car ac is not blowing cold air

2. There is a loud noise (squealing or grinding) from the compressor

3. Stiff compressor clutch

4. The circuit breaker is tripping

How to fix it?

Repairing compressor issues can get complicated. Most of the time, it is much better to replace it. To avoid AC compressor failure, you should run your AC for 15 minutes at least once every three weeks.

5. Electrical problems

Another reason for the AC not blowing cold air in car issue could be electrical. Some of the components of the AC system are electrical. Electrical problems such as blown fuse may stop the AC from working.

How to fix it?

You can check the fuse on the power distribution panel under the hood. Check for any blown fuse in the AC fuse box and replace it with a new one. You may refer to the manual to find its location.

However, if the fuse gets blown up again, there could be a short in the system. Usually, the short is related to the compressor clutch coil and should be replaced immediately.

How much does it cost to repair a car AC not blowing cold air?

In case you don’t want to take the DIY route in fixing your car’s AC, you can expect the following costs:

1. A full inspection and diagnosis may costs you $80 to $120

2. If your AC needs a recharge, a refill can cost $80 to $150

3. Minor repairs such as cleaning, clog removal, leaks, and clutch replacement can cause $150 to 800

4. In case the AC needs major repairs or has multiple issues, it may cost more than $1000.

These are estimates and may vary depending on your car’s model and location.


The problem with car air conditioning can be frustrating and dangerous during summer. If your car ac is not blowing cold air into the vents, it could be due to the failure of one of the system’s components. Some of the causes can be diagnosed and fix easily.

Moreover, make sure you have technical knowledge of how each component works before you proceed with DIY repairs. This is to avoid incurring more damage and repair costs.

If you cant diagnose the AC not blowing cold air in car issue, it is best to bring it to certified AC technicians.

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Related: Can I Sleep in my car with the AC on?

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