Ac low side pressure too low: Understand the problem and reasons

Just imagine your vehicle’s AC stops working on a humid afternoon? Well, the temperature inside the car would become unbearable and you wouldn’t have any other option but to travel in that hot vehicle.

AC transferring the whole pressure on the ‘low’ side while the compressor being too high than usual is not something unusual. Just like other components or parts of the car, AC is also another machine that requires maintenance and can get worse with time.

It would not matter much to the people living in colder parts of the world. However, human beings who reside on the hotter side of the globe wouldn’t like the fact that their car’s ACs are not operating or functioning in the best condition.

One of the basic reasons for AC being less efficient could be the AC low side pressure too low or imbalance of power and pressure. Nevertheless, there are several other reasons which we will highlight in this article.

Moreover, we will understand how the AC works, why it is necessary for a vehicle, and what causes the AC to be low in performance.

The purpose of an AC in a car has changed over the years?

People are living in a misconception that the basic duty of an AC is to provide cool air in the car. However, the main purpose of an air conditioner is to pull out the heat and humidity from the vehicle. Surely, adding cool air is another function of it but cannot be counted as the basic or primary purpose of an air conditioner.

Since this technology was introduced 60 years ago, it has not changed much. Yes, improvement in terms of technology has been made, but the fundamentals are still the same.

How to test your car’s AC pressure?

Just like the vital parts and components of your vehicle, you cannot survive a sunny or hot day without AC functioning properly. Moreover, it is not that easy to fix the AC on your own. Experts recommend taking your vehicle to a trusted mechanic to get issues resolved, rather than doing something which can cause a bigger problem.

Some parts or wires of an AC are quite tricky and any minor mistake can become costly for you.

On the other hand, with the improvement in technology, it has become relatively easier for you to check the pressure of the AC on your own. There are gauges available on different sites such as Amazon and multiple retail outlets. You can purchase one for around $50-100 to check whether the pressure is up to the mark or not. That being said, finding a reliable gauge might become a difficult task for you.

To check the pressure yourself, you should refer to a manual or directory provided by the manufacturing company. Instead of listening to inefficient people’s advice, take the right route of doing it professionally. You can check general readings available on the internet or in the manual to make the right comparison.

Why is AC low side pressure too low?

Sometimes the readings you’re receiving on the gauge can be accurate yet the AC’s pressure might not be up to accurate. Let’s understand what could be the possible reasons for the ac low side pressure being too low.

Expansion valve or orifice tube is cracked or clogged

You never know what might have happened in the technical part of the AC. Well, the expansion valve being torn off or the tube is full of clog or dirt might be the reason for your car’s AC not functioning properly.

Due to dirt or clog, it becomes harder for the liquid refringent to reach the evaporator coil. This is the reason the blow of air is not sufficient. The compressor might be working efficiently and sucking the hot air, however, there is not anything significant for it to suck.

System being undercharged

Just like the maintenance of other crucial parts or components of the car, it is essential to maintain AC as well. The compressor would be working at its full pace, yet the vent would be producing warm air.

What could be the reason? Well, the AC system needs to check at least once a month. If the power of pressure from the engine is not adequate, it’s high time for you to understand that the AC system needs to be charged.


Any vehicle or car would be incomplete without a well-conditioned air conditioner. It’s the human psyche that whenever he/she goes out to the market to purchase a car, AC is one of the essentials on which they’ll focus.

It’s important to keep your car’s AC maintained, otherwise a bright sunny day could ruin your whole mood. Beat the heat with a properly functioning AC.

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