AC Works on One Side of Car – Causes and Solution

The Air conditioner in your car is essential for a better driving experience, especially in the hot summer. When AC works on one side of car only, it’s typically a symptom of an HVAC system temperature problem. The issue could stem from low refrigerant, faulty temperature sensors or a malfunctioning blend door actuator. Blend doors regulate cold airflow distribution when stuck or broken, one side may blow hot air while the other side remains cool.            

Many factors may cause this, including low refrigerant level, damaged temperature sensor, bad door actuator, and more.

ac works on one side of car

Causes of AC Works on One Side of Car

You might be wondering why AConly works on the driver’s side. If your AC works from one side, it could be caused by numerous issues, which we will discuss. Some problems could result from AC settings, while others could be more complicated, like damaged blend door actuator, faulty temp sensor, or low Freon etc.

Below are some of the causes of your AC working on one side.

1. Low Refrigerant

Refrigerant is a chemical substance provided for a car’s cooling system that helps cool the air present in the car’s interior. Unfortunately, many people ignore their vehicle’s refrigerant.

When the refrigerant in the engine is low due to leaking, the AC cannot circulate cold air properly. It is why your AC is not working well, why thecar ac works only when moving, or works from one side. Many other people experience their ac blowing hot air due to low refrigerant. 

Also, driving with a low refrigerant while the AC is on could pose a future risk to your engine. It will increase the engine’s temperature, which could lead to overheating.

When you notice that your AC is not functioning right, the first factor you should consider is the refrigerant and cooling fluids.

2. Damaged Temperature Sensor

If your ac blows hot on driver side, and cold on the passenger side, it may be caused by a bad temperature sensor.

The temperature sensor is an integral part of how your AC system functions. It determines the temperature of different vehicle parts, including the interior. The information obtained from the temperature sensor is then transferred to the Powertrain Control Module (PCM) for use.

The wrong signal is sent to the PCM when the temperature sensor fails or malfunctions. As a result, the PCM will wrongly regulate the AC causing one side to work and the other to stop. Engine may overheat while ac is on due to this issue.

3. Bad Blend Door Actuator

A blend door actuator serves the purpose of controlling and regulating the climate control system. It is a small electric motor that looks like a plastic box.

Just like many electrical components in the vehicle, the blend door actuator can get damaged over an extended period of use. This part works directly with the HVAC to provide the proper temperature for your driving experience.

Once the blend door actuator is not working fine or the ac only works on high, then the HVAC cannot function properly 

4. Wrong AC Control Settings

A common cause of your AC working on only one side is a wrong AC control setting. Many vehicles come with settings that allow you to lower one side and increase the other side. Unfortunately, many people are unaware of this and do not know how to make ac colder or work from both sides with the control of this feature.

This issue is one of the main reasons one side of the ac only blows cold on the passenger side.

How to Fix AC Blowing On One Side

Fixing your AC blowing from one side depends on the cause of your malfunctioning AC. Since there are many causes of this problem, you would have to first find the actual cause of your AC problem before fixing it.

You must check the related parts with the previous causes to do this. Once the cause has been found, then you can move on to fix it.

Below are ways to fix a car’s AC blowing from one side

Recharge Air Condition

It is easy to fix if the problem with your Ac is related to a low refrigerant. All you need to do is recharge the Ac.

The procedure is relatively easy, but you also must be well-informed about the necessary factors to be considered during the recharge. For instance, too much Freon is not good and what type of refrigerant does your vehicle use?

Cars made before 1994 make use of the R-12, while others may make use of the R-134a. To better know your vehicle’s refrigerant, consult your car’s manual. 

Replace the Damaged Temperature Sensor

Temperature sensors are one of the most common causes of AC problems. Once you have discovered that the problem is a temperature sensor, you will have to replace it.

Finding the temperature sensor may be tricky because the location varies with vehicle brands. For example, temperature sensors may be behind the bumper, while on other cars, they could be in the door.

Replace Blend Door Actuator

The blend door actuator is located on the driver’s side, close to the accelerator pedal and HVAC box. When it becomes damaged, you will have to replace it. However, it is straightforward, so you must uninstall the old actuator and install the new one. 

Reset the AC Control

You do not have severe pain if your AC problem is related to control settings. Locate your vehicle’s manual and follow the instructions to operate your AC correctly. 

How to Properly Clean Car Ac

It is essential that you regularly clean your AC, depending on how frequently you use your AC will determine how much you will clean it. To clean your vehicle’s AC, you must clean the car AC condenser and Air vent.

You will need a foam or paint brush and cleaning solutions to clean the vent. First of all, attach small foam to a stick to make cleaning easier. Then apply the cleaning solution to the foam and use it to clean the vent slat.

You may have to replace the cabin air filter with a cleaner AC. Many modern cars have a filter inside the cabin within the glove compartment.

To access the filter, you will have to remove the compartment tabs. In most cars, after removing the panels and tabs, you will have the filter under the dashboard. Once you have seen the filter, unclip and remove it. You can then go on to fix the new filter.

It is recommended that you replace the filter every 15,000 miles or less.

In addition, you should spray disinfectants into the vents to kill off all forms of bacteria or fungus.   

How to Replace Blend Door Actuator

If the problem of your AC system can be related to a Blend Door Actuator., then you will need a replacement. Replacement is relatively easy if you have the proper steps to follow. Below is a brief step-by-step guide to replacing your Blend Door Actuator.

  1. Install your vehicles glove box
  2. Locate the temperature Door Actuator
  3. Remove all connected wiring and bolts and uninstall the actuator
  4. Arrange the shaft with your new actuator
  5. Fit in the actuator
  6. Install all bolts and wiring
  7. Ensure the actuator is working using the AC control
  8. Fit in the glove box

How Much Does it Cost to Replace a Blend Door Actuator?

The blend door actuator cost will bebetween $300 and $400 including labor costs. Labor costs will be from $100 to $150, parts prices vary from $200 to $250, and this excludes taxes.

However, the cost to replace the Blend Door Actuator depends on many factors, including the brand of the actuator, where you will be getting it, and whether or not you have it replaced yourself.

Also, it would help if you understand that the vehicle you are replacing the actuator in could influence the price. Some vehicles’ actuators can cost a lot more than others.

ac only blowing cold on passenger side


Ac working on one side of the car is a future problem that most cars experience with their cooling system. When this happens to your vehicle, do not panic, all you have to do is appropriately diagnose the problem. Once you can get the cause of the problem, then fixing it will not be a big deal. Getting a professional will be helpful in adequately diagnosing and fixing your AC problem.

Akindayini Temiloluwa

I am Akindayini Temiloluwa, an automotive expert writer and car enthusiast. I have over three years of experience in the automotive writing niche and have completed over 300 pieces of content from 50 projects. I have vast knowledge and skill in vehicle repairing, all mechanical work, car upgrades and maintenance. My goal as an automotive content writer is to simplify the most challenging concepts for my readers, help them self-diagnose what may be wrong with their vehicles and offer real value for their time.

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