Car AC Stops Working When Hot Outside – What To Do Now?

Sometimes your car air con blows warm air, which causes you to wonder why your car AC stops working when it is hot outside.

The blend air door does not switch from heat to cold air.

It’s possible to fix the problem, but it can lead to a costly repair. Don’t forget to read our article for some tricks to protect your AC.

Car AC

Air Conditioning System

Before we answer the question, we need to know why my AC doesn’t work when it’s outside. We will look at how each component of the AC system functions.

Air Compressor

The gas is being compressed by the compressor. Low temperature, low-pressure gas is the first thing that comes to mind when you think of refrigerant.

High-temperature, high-pressure gas is created when it is converted into a compressor. If the AC isn’t working when it’s hot outside, there’s something wrong with the component.


When the high temperature, high-pressure gas moves from the compressor to the condenser, the condenser will perform like a mini radiator with the help of the condenser fan on top.

At this stage, the condensation transforms into a high-pressure fluid.


The expansion valve can be blocked when the refrigerant is frozen.

There is a dryer and a receiver that can be used to remove the humidity and prevent the liquid from freezing.

Expansion Valve

The amount of coolant that will go through the system is determined by the expansion valve.

The temperature and pressure will be affected by the expansion of the coolant at this stage.

The issue of my car’s ac stopping working when it is hot outside can be traced to a faulty valve.


The heat from the Refrigerant is absorbed by the Evaporator and it goes to 32 degrees. It is the temperature that becomes gas again.

The cycle starts again after low pressure, low temperature gas comes back to the compressor.


The main reason is that pressure changes. It’s possible that a temperature sensor is malfunctioning, or that high temperatures outside will cause the coolant to expand.

The car AC stops working when these factors are present. In the low-side pressure, there is a stop-gap to be found. It’s a good idea to do the AC maintenance periodically.

Refrigerant Leakage

It is one of the most common reasons for car AC not cooling down during hot weather.

Since the refrigerant keeps circling and when it turns to gas status again, it is difficult to tell where the leak originated.

The acidic combination can be caused by the leaking spot and the condensation that gets inside the cooling system.

It can cause further damage to the AC. Car AC isn’t cool, but the problem is more serious than that. It is possible to use the leak seals if there is a small leak.

Bring your automobile to the auto repair shop for a visual inspection and professional repairs if you have a bad coolant leak or don’t know what to do.

Faulty Compressor

The heat transfer process and the AC compressor both play a part in moving the coolant. A bad compressor is usually due to a lack of use.

When you don’t use your cooling system for a long time, it’s understandable why it doesn’t work when it’s hot outside. It is suggested to run it for 15 minutes every few weeks.

A stuck compressor clutch can damage the compressor and cause the ac to stop working. Your AC will keep running if it’s stuck.

The compressor will be turned off if it is stuck. If you have a problem, consult with the automobile service. It’s better to replace the compressor than to rebuild it.

Condenser Issue

Keeping the air cool is accomplished by taking the humid air and sending it out. It can be a sign of a broken condenser if your car’s AC struggles in the heat.

The front grille has a chance for debris to come inside and block the lines because the condenser is behind it.

There isn’t a big problem with liquidating the blockage in the coil. It is necessary to replace the condenser if it is in worse shape.

Electrical System Problems

An electrical issue can cause the AC in the car to not be cold. To figure out the root of the problem, you must disassemble the mechanism.

A blown AC fuse, a faulty switch, or a control module issue can be what it is. It isn’t hard for you to fix electrical systems if you have some knowledge.

You should get to the bottom of the problem. Acid can build up and cause damage if it’s put off.

If you are aware that AC doesn’t work when it’s hot outside, you should seek help from experts.

Broken Cooling Fans

The broken cooling engine compartment fans are one of the reasons that an AC doesn’t work when it’s hot outside.

The fan blade helps move the refrigerant and reduce the heat in the system. The process of cooling can be affected if the cracked one is present.

There are a variety of causes for this improper work, such as an electrical short, blown fuse, or road debris damage. The only thing you can do to fix your cooling system replaces it.


Expel The Air

You will be trapped in an extreme heat box if you don’t emit the warm air out of your vehicle before you drive.

Open and close the front windows for one minute when you scroll down. It is advised to open the rear windows for 30 seconds while driving.

Set The AC To Low

It is possible to prevent the situation of car AC blowing cold air when it is hot by using it at low mode.

It takes the air from inside the car, which is usually hotter than the outside one if you set it in high mode.

Time To Drive

If you drive at the sunniest time of the day, there will be more strain on your cooling system.

If you want your car to work on hot days, you should drive in the cooler mornings or evenings.

Change The Components

The car air conditioner can’t keep up on hot days as it overloads in the summer. Make sure the components work efficiently by changing them.

Maintenance Service

The situation of a car AC not working in hot weather and other problems can be avoided if you book a regular maintenance service.

It’s a good idea to bring your vehicle to the repair shop. Professional mechanics can prevent heat-related issues from happening in the first place.

Car AC


You can understand why your car’s AC stops working when it’s hot outside and how to fix the exhaust issue.

The fewer problems you will have with your cooling system, the better you will treat your vehicle. Don’t forget to use our tips to save your air-con during the summer.

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