Car AC Stops Working When Hot Outside: Causes and Solutions!

It would be a nightmare If you must drive your car on a hot day when the car’s AC stops operating or is not cooling enough. We are sure that you don’t want to sit in your vehicle when it’s almost 100 degrees outside and the engine heats up, constantly blowing hot air into your car. These are the reasons why you need to find culprits that can affect your car’s AC. So what are the causes and how can you fix when your car AC stops working when hot outside? Let’s find out the truth with us in the article!

Why Your Car AC Stops Working When Hot Outside.

A car air conditioner is not cool or sometimes cool sometimes not …when it is hot outside is one of the very common problems. This is a sign that the car’s air conditioning system is having problems. It is necessary to check the cause and handle it soon to avoid the issue becoming more and more serious, affecting the lifespan of many important parts, causing fuel consumption, and affecting your driving experience. 

Car air conditioner errors are not cool

These are some of the problems that your air conditioner may experience when driving in hot weather:

  • Poorly cooled air conditioning system: This is a condition in which the air conditioner has been turned on at a high level but you still do not feel cool when driving your vehicle, besides there is a situation where the air coming out of the cabin has a bad smell.
  • AC  is completely not cool: This is a condition where the air conditioner loses the cooling effect even though the cooling system has been started.
my ac in car is not working
Why my ac in car is not working? Let’s find the reasons! (Photo:

7 reasons why your car AC is not working in hot weather?

The hotter it is outside, the harder it will be for your car’s air conditioning to work. The temperature increases which will put extra strain on your vehicle and the AC system, from batteries and belts to hoses and fluids, requiring each component to work harder to keep the temperature inside your car cool. When the temperature heats up, it causes the coolant to expand and makes the temperature malfunction. These are the reasons that make your AC stop working. However, there are still some other reasons which can explain the situation your car AC stops working when hot outside:

Clogged filter

A clogged air conditioner filter is often one of the causes of the condition that the air conditioning system stops working or runs normally but is not cool enough. Because it is responsible for filtering dirt and impurities, after a long time of operation, the air filter will be covered with dirt. If not maintained periodically, dirt easily accumulates into thick blocks to prevent wind circulate in your car, causing the internal fan to not draw enough air.

An outdoor unit is dirty

The outdoor unit is usually installed in front of the radiator and the engine fan. This part has the role of exchanging heat, dissipating and discharging heat to the outside. When the part is accumulated with too much dirt, it will cause poor heat dissipation, greatly affecting the cooling efficiency and making your AC not cool. Drivers should check the outdoor unit as soon as the air conditioner shows signs of this problem.

Blocked condenser

The function of the condenser is to convert the Freon gas into a liquid form. It occurs in a heat exchange process, in which the heat of the refrigerant is pushed out and exchanged with the outside air. If the condenser is malfunctioning, the refrigerant will stop flowing, preventing cool air from being released. At that time, your AC system can’t produce cold air which causes the AC compressor to overheat. 

Refrigerant gas issues

The reason for the lack of gas in your AC system is that the gas has not been refilled for a long time. This situation will cause the air conditioner to operate inefficiently, not blowing cool air into your vehicle.

In case of excess gas, the pressure will be higher than normal. In addition, overcharging gas can affect other components in the system, even causing an explosion. The obvious sign of excess air conditioning gas is the phenomenon of the machine running slower, and the phenomenon of closing / disconnecting the cooling process. 

The third case that can make your air conditioner not cool is a refrigerant gas leakage. At this time, the pressure will drop below the standard level and the AC system will stop working.

Car AC lines freezing up

The indoor unit is responsible for absorbing and reducing the temperature of the air passing through it. However, over time, this part is dusty, easy to breed bacteria, and mold, causing unpleasant odors. In the long run, the indoor unit will be frozen, with dense ice clinging to the louvers and openings, making it difficult for air to circulate. In addition, the phenomenon of freezing can also be caused by damage to the throttle valve, air conditioner fan, or sensor system, … Frozen indoor unit will cause the car’s air conditioner to stop operating.

Electrical system problems

Responsible for controlling the operation of the whole system – if the circuit or other electrical components malfunction, the air conditioner will not work. Accordingly, users should check the circuit, and capacitor, … to identify the exact cause.

Faulty cooling fan 

Having a problem with the cooling fan is also one of the reasons why your car AC stops working when hot outside. If the blower is turned on, but it is weak or not cool, it may be due to the following reasons: broken electrical circuit, faulty capacitor, damaged contactor coil, or short-circuited fan motor…

>> Related post: Car AC Blowing Hot Air: Troubleshooting the Dilemma

How To Handle When Your Car AC Struggles In Hot Weather?

car ac doesn't work when it's hot outside
You should turn on the AC at a low speed when driving your car in hot weather. (Photo:

Your car air conditioner can’t keep up on hot days is one of the signs that the air conditioning system is having problems. It is necessary to check the cause and fix it soon. We understand that your AC system not working in the hot weather can be a very frustrating thing to happen when driving your vehicle. So we want to share with you some methods to prevent this problem.

Your air conditioning system will have to operate at full capacity when the outside temperature heats up. So if you have to drive in such harsh weather conditions, you should turn on the AC at a low speed. This will reduce the pressure on the cooling system as well as enjoy the cool air while driving. 

Clean and change the air conditioner filter periodically

Dirty air filters will reduce the amount of air circulating, hindering the cooling process of the air conditioner. Therefore, users should pay attention to regular cleaning to ensure effective equipment operation. In the case of excessive dirt accumulation, drivers may consider replacing the air filter with a new one. The replacement time should be based on the manufacturer’s recommendations and operating conditions. Normally, after the distance ranges from 16,000 – 24,000 miles, car owners should replace the air filter with a new one.

Limit driving in hot weather conditions

When it’s hot outside, you should limit driving, avoiding the hottest times of the day can help you reduce strain on your AC system.

Check the entire AC system

Drivers should take the car to the repair center for a technician to check the entire system, and find the cause. Fixing the problem of why the car AC doesn’t work when it’s hot outside. In addition, the internal components also need a thorough cleaning to ensure that the device’s operability is restored. If the cause of your air conditioner not cooling is a faulty compressor, you must repair or replace it. The cost of replacing a new one depends on the type of vehicle and the manufacturer of the air conditioner compressor.

Regular maintenance

Routine maintenance is an important remedy for the condition of the car air conditioner not cooling. In particular, if the vehicle often has to operate with high frequency in a dusty environment. Drivers should maintain it once a year to check and promptly handle damage.

>> Read more: Broken Car Air Conditioner? Try Automotive Air Conditioning Repair at Home

Closing Thoughts: Car AC Stops Working When Hot Outside

Driving without an air conditioner, especially in hot weather, can be risky and challenging. It does not only make you feel uncomfortable but potentially many health risks. So we hope that our article will keep you cool on those extremely hot days. If you have any questions, don’t hesitate to write in the comment box below.