Updated at: 13-07-2022 - By: Lucas

Now that summer is here, the days are hotter than they’ve ever been. A drive can be a great way to stay cool, but only if the car’s air conditioning is working.

Here are the top 5 reasons why your air conditioning might be “warm.”

#1 Refrigerant Leak

Freon is the chemical that cools the air before it is blown back into your car. For the air conditioner in your car to work well, it needs a certain amount of Freon.

If your car’s air conditioner starts acting up and the air it blows out is no longer cold, it may be because of a Freon leak.

There are many things that can cause these chemical leaks, such as:

Damaged hose

Loose gasket

Loose connection

Freon leaks don’t always have to be big. In fact, you might not realise you have one right away, though you might think your car’s air conditioning is a couple of degrees warmer than usual.

A slow, constant Freon leak like this can take years to show up. A difference of one or two degrees in the car’s air conditioner one summer becomes another difference of one degree the next summer, and so on, until all of a sudden, the air is no longer cold.

For the problem to be fixed, a professional needs to look at the car, find the broken parts, and replace them. After that is done, the Freon levels need to be topped off.

#2 The Blend Air Door is Stuck

Car AC Not As Cold As Usual-2

The part of the car’s air conditioner that swings across the ventilation system and stops warm air from getting in is called the “blend air door.” It also lets cool air come back out of the vent.

Sometimes, the door to the blend air gets stuck. When that happens, it doesn’t matter how high you set the dial on the car’s AC. When the blend air door is stuck, the warm air doesn’t get shut off like it should, so it just goes back into the car.

Most of the time, you don’t have to put anything new in to get the blend air door to stop sticking. But the system is fragile and hard to get to, so it can be hard to change.

If you think your car’s AC isn’t cold because the blend door is stuck, look for and listen for these signs:

Symptom 1: Noise

The AC system in your car is usually located behind the centre dashboard. That makes sense, since that’s where the AC controls are, on the panel with the knobs.

If you hear noise coming from behind the dashboard while you’re driving, it’s probably because the blend door is broken.

To figure out what’s wrong, play with the car’s AC controls. If the noise gets worse as you do this, it could be because of the gears that keep that blend door moving.

Symptom 2: Knocking

When the car’s air conditioner breaks down, knocking isn’t always a sign.

But if you do hear it, you can be sure that your car’s AC is blowing warm air through the car because of a broken blend door.

Symptom 3: Inconsistent Airflow

Most of the time, a stuck blend door lets warm air into the car because it can’t close properly. But if the blend door isn’t completely stuck, the airflow may just be a bit uneven.

This happens because the door isn’t doing its job as well as it should.

If the airflow isn’t consistent, you might also not be able to change the temperature. Depending on what the car’s AC can do, it may also switch from low vents to the defroster all the time.

#3 The Car’s AC Compressor Doesn’t Engage

Car AC Not As Cold As Usual-3

If the car’s AC needs Freon to work, then the compressor, which squeezes the Freon, is the beating heart of the system. As soon as the Freon starts to spread out, it gets very cold very quickly.

This process of expanding and cooling is how the air conditioner in your car makes cool air on hot days.

But if the compressor doesn’t work, the Freon never gets compressed, so it can’t expand.

There are many things that can make a compressor act up, such as:

Low levels of Freon

Electrical fault

Engine got too hot

Aside from an AC system that acts up more than usual, there are other signs that the AC compressor is failing:

The compressor makes a lot of noise as it works.

Moisture leaks

Not moving or staying still: compressor clutch

Trips of the circuit breaker

Suction lines that are broken or damaged

Wires that are broken or hurt

Some of these might not be obvious to you right away until you start working on your car. So, if you think your car’s compressor is to blame for the AC blowing warm air, you may need to take it to the shop.

#4 Blocked or Broken Condenser

The compressor is in charge of squeezing the Freon and making it work as a coolant. The condenser is in charge of turning the coolant Freon back into a liquid.

Unsurprisingly, the condenser can’t work right when dirt or broken parts get in the way. Instead, the Freon stops being able to move like it should. This slows down the cooling process, so the air conditioner in your car blows warm air instead of cool air.

Besides warm air from the air conditioner, there are other signs that your car’s condenser needs to be checked:

Symptom 1: Burning Smell

Because the Freon isn’t moving as it should, you and the rest of the car’s systems start to get hot. If the car doesn’t have a working condenser, parts that get too hot will start to burn.

So, if the air conditioner in your car stops blowing cool air and you think you can smell something burning, it’s probably because the condenser isn’t working.

Symptom 2: Overheating When Idle

In a similar way, if the Freon can’t get through the AC, it can’t get rid of the heat either. The heat builds up inside the car.

Usually, the cool air from the AC keeps the heat under control, but if it can’t, don’t be surprised if your car is too hot when you stop driving.

Symptom 3: Noticeable Coolant Leaks

Since the refrigerant in the condenser is under very high pressure, you will know if it leaks.

Check for puddles under and around the parts of the car that are important. But remember that if you see leaks, you need to replace the condenser, not just fix it.

Symptom 4: Warning Lights

Some cars have a light that turns on when the AC stops working, which is helpful. If you have one of these cars and notice that the air conditioner isn’t blowing cold air, check the dashboard to see what it says.

If you’re not sure if your car has this feature or not, you should be able to find out by looking through the manual.

#5 Electrical Faults

Lastly, if your car’s air conditioner only blows warm air, it could be an electrical problem.

Many of the parts of a car’s air conditioner are electrical, and just like anything else that is electric, they can blow or trip a fuse.

If you don’t know much about this kind of electrical work, it’s best to take your car to a shop and have a pro look at it. This work can be tricky, and you don’t want to end up with more problems than when you started.


Even though the cause may be different, if your car’s air conditioner blows warm air, it’s clear that something is wrong with the system.

Pay attention to any signs or symptoms that might help you figure out why your car’s AC isn’t blowing cold air anymore. If you can’t fix it yourself, take it to the nearest garage to get it fixed.

Keeping cool in the summer is important, and a drive through the country can be the best way to do that when your car’s air conditioning works.