Ac In Car Blows Cold Then Warm

AC in Car Blows Cold Then Warm: Causes and Solutions

When your car’s air conditioner (AC) starts blowing cold air and then suddenly switches to warm air, it can be a frustrating and uncomfortable experience. This issue can be caused by several factors, ranging from refrigerant leaks to electrical problems. In this article, we will explore the common causes of this problem and provide step-by-step solutions to help you resolve it.

Causes of AC Blowing Cold Then Warm

  • Refrigerant Leaks

Refrigerant is a vital component of an AC system. It absorbs heat from the car’s interior and releases it outside. If there is a leak in the refrigerant lines, the system will not have enough refrigerant to cool the air effectively, resulting in warm air being blown into the cabin.

  • Faulty Compressor

The compressor is the heart of the AC system. It compresses the refrigerant gas and pumps it through the system. If the compressor fails or becomes weak, it will not be able to circulate the refrigerant properly, leading to insufficient cooling.

  • Clogged Condenser

The condenser is located in front of the radiator and helps dissipate heat from the refrigerant. If the condenser becomes clogged with dirt or debris, it will not be able to release heat effectively, causing the refrigerant to overheat and lose its cooling capacity.

  • Electrical Problems

Electrical problems, such as a faulty AC relay or a blown fuse, can also cause the AC to blow warm air. These problems can interrupt the power supply to the AC system, preventing it from functioning correctly.

Solutions for AC Blowing Cold Then Warm

  • Check Refrigerant Levels

The first step in troubleshooting an AC system that is blowing cold then warm is to check the refrigerant levels. You can use a refrigerant gauge to measure the pressure in the system. If the pressure is low, it indicates a refrigerant leak.

  • Repair Refrigerant Leaks

If a refrigerant leak is detected, it is crucial to have it repaired as soon as possible. Refrigerant leaks can cause further damage to the AC system and can also be harmful to the environment.

  • Replace Faulty Compressor

If the compressor is faulty, it will need to be replaced. This is a more complex repair that should be performed by a qualified mechanic.

  • Clean Condenser

A clogged condenser can be cleaned using a hose or a pressure washer. Be careful not to damage the condenser fins while cleaning.

  • Troubleshoot Electrical Problems

If electrical problems are suspected, it is recommended to have the vehicle inspected by a mechanic. They can diagnose the electrical issue and repair or replace the faulty components.

Advantages and Disadvantages of AC Blowing Cold Then Warm


  • Temporary Relief

While the AC blowing cold then warm is not an ideal situation, it can provide temporary relief from the heat. The cold air intervals can help cool down the cabin, making the ride more comfortable.

  • Early Warning Sign

The AC blowing cold then warm can be an early warning sign of a more serious problem with the AC system. By addressing the issue promptly, you can prevent further damage and costly repairs.


  • Discomfort

The fluctuating temperatures can be uncomfortable for passengers, especially during hot weather.

  • Reduced Fuel Efficiency

A malfunctioning AC system can put extra strain on the engine, leading to reduced fuel efficiency.

  • Potential Damage

If the underlying cause of the problem is not addressed, it can lead to further damage to the AC system or other components of the vehicle.

How to Prevent AC from Blowing Cold Then Warm

  • Regular Maintenance

Regular maintenance of the AC system, including checking refrigerant levels and cleaning the condenser, can help prevent problems from developing.

  • Avoid Overuse

Avoid using the AC at maximum capacity for extended periods. This can put extra strain on the system and lead to premature failure.

  • Park in Shade

Parking your car in the shade can help reduce the workload on the AC system, as it will not have to work as hard to cool the cabin.

  • Use Sunshades

Using sunshades on the windshield and windows can help block out sunlight and reduce the heat buildup inside the car.


An AC system that blows cold then warm is a common problem that can be caused by various factors. By understanding the causes and solutions discussed in this article, you can troubleshoot the issue and restore the AC to proper working order. Remember to address the problem promptly to prevent further damage and ensure a comfortable driving experience.


  • Why does my AC blow cold then warm after a certain amount of time?

This could indicate a refrigerant leak or a faulty compressor.

  • Can I fix the AC myself if it’s blowing cold then warm?

It depends on the underlying cause. Simple issues like cleaning the condenser can be done at home, but more complex repairs should be left to a qualified mechanic.

  • How much does it cost to fix an AC that blows cold then warm?

The cost of repair will vary depending on the cause of the problem and the extent of the damage.

Closing Statement

Maintaining a properly functioning AC system is essential for a comfortable and safe driving experience. By following the tips and advice provided in this article, you can prevent or resolve issues with your AC blowing cold then warm and enjoy a cool and refreshing cabin on hot days.


The information provided in this article is for general guidance only and should not be taken as a substitute for professional advice from a qualified mechanic. It is recommended to consult with a mechanic if you encounter any problems with your vehicle’s AC system.