Top 5 Reasons Why Your Car AC is Not Blowing Cold Air

We are now a month away as the Hawaiian summer heat makes waves, and it is most likely the time of the year when you need your car’s air conditioning system the most.


However, issues can be inevitable. As you turn on your AC, you notice it’s not blowing cold air or cooling your cabin enough to beat the heat.


Why is this happening?


This can be caused by several factors, which is why we came up with the idea of writing this article to let you know the 5 common car AC system problems and solutions you can do to address these problems immediately.


So, let’s dive right in!

Main Components of Car Air Conditioner

As a car owner, it is vital for you to get to know the main components of your car’s air conditioning system, so you will be able to understand and identify where the problem area is and how to resolve the underlying issues possibly. Below are the main components of a car’s air conditioning system:

  1. Compressor

The compressor pressurizes and cycles the air conditioning system’s refrigerant. It has a magnetic clutch that activates in response to switched input or electronic demand.

  1. Condenser

The condenser is a slim, radiator-like component positioned behind the car grill. The condenser transforms the refrigerant from a gaseous to a liquid form when air passes over it so as to lose heat in the process.

  1. Accumulator/Dryer

Your automobile can have either one of these main components depending on the type of air conditioning system it has. A receiver dryer is a critical element found in expansion valve systems. On the other hand, an accumulator dryer is only present in orifice tube systems.

  1. Orifice Tube/Expansion Valve (Measuring Devices)

All car air conditioning systems depend on a specific metering unit to determine and control the refrigerant flow. Some systems use expansion valves, while others use an orifice tube.

  1. Evaporator Core

The evaporator core is a compact heat exchanger whose primary function is to absorb heat. As the refrigerant travels through the condense, it changes from liquid to gas. The heat gathered from within the cabin is then absorbed by the evaporator 


A/C System Sensors

Aside from the main components, an automobile air conditioning system also includes numerous sensors to provide helpful feedback to maintain the efficient running of the system. The following are the sensors and their respective functions.

  1. Ambient Temperature Sensor

Contemporary automotive air conditioning systems use the ambient temperature sensor to transmit cabin temperatures dynamically. The data is then used to improve cooling efficiency and keep cabin temperatures steady in various conditions.

  1. Low-Pressure Switch

A low-pressure switch functions as a detector for the percentage loss in refrigerant and the accompanying lubricating oil. It is activated to turn off the system’s compressor when low-side system pressures drop below a predetermined level to reduce the risk of failure.

  1. High-Pressure Switch

A high-pressure switch is made specifically to identify refrigerant over-pressurization in an air conditioning system. It activates when system pressures increase, which stops the compressor clutch from working.


How Does Your Car Air Conditioning System Operate?

An air conditioning system needs a refrigerant, such as R-134a. The refrigerant is compressed into a liquid and brought to a high-pressure state by the compressor in your car, driven by the serpentine belt. This pressure pushes the liquid through the hoses of your AC hose assembly, which transport refrigerant throughout the system and out of the compressor. 


No matter what system your vehicle uses, pressurized refrigerant pushes from the compressor to the condenser on the high-pressure side of the system to cool off before reaching the AC evaporator core found on the low-pressure side.


Before the liquid inside reaches the AC in-line filter to filter out debris that could contaminate the system, it absorbs heat from the liquid inside the condenser, similar to a miniature radiator where the AC hoses come into contact with the outside air. 


The now-cooled refrigerant passes through either the expansion valve or the orifice tube to the low-pressure side of the system. The refrigerant can then absorb heat from the air passing through the evaporator fins through the evaporator core in a gaseous state. Once the warm refrigerant travels back to the compressor, the cabin is then cooled.


However, this process is greatly dependent on the type of system you have.


Causes A Car Air Conditioner Is Not Blowing Cold Air

  1. Low Refrigerant Levels

Low refrigerant levels are among the most frequent causes of poor air conditioner cooling. The refrigerant is responsible for keeping your cabin cool. 


Refrigerant leaks can be due to unforeseen collisions or accidents, and it can be quite challenging to pinpoint precisely where the damage is because the leaks are within the joints. The oily substance that collects around the hose is a sign that there is leaking.


Before your AC system is recharged, finding and fixing the leak as necessary is crucial. 


However, a word of caution: avoid repairing the issue by yourself as you do not know how to manage the technical issue or the extent of such damage. Therefore, before going for a long drive, have it checked by an automotive AC repair shop. 

  1. Electrical Issues

In modern vehicles, numerous fuses, sensors, and switches can be damaged, preventing the air conditioner from functioning. Faulty blower fans, engine cooling fans, and relays can impact the cooling performance of your air conditioning system. 


Furthermore, the engine control module or ECM can prevent the AC from starting if it detects an overheated engine or problems with your emission control system.


Ensure that all the electrical connections are clean, tight, and safe. Use a cheap 12V test light or digital voltmeter to check the fuses. You can also analyze the defective area, seal it with electrical-resistant tape, and connect the other end with a connecting wire.


However, having your car checked by a certified car aircon repair shop is best and let the professionals handle the situation.


  1. Clogged Cabin Filter

If the air conditioner is not cool enough, a dirty or clogged cabin filter can be one of the common problems. You can actually diagnose it on your own– just remove the cabin filter from the dashboard holder. An unclean filter can be one of the causes why there is inadequate air inflow to your cabin. If this happens, make sure to clean or change them.


This is something that you can DIY: buy an authentic cabin filter and swap out the old one. If the problem still persists, stop by one of your local auto repair shops, like Car Geeks.


  1. Moisture or air contamination

An automobile’s air conditioning system must be free from air and moisture impurities to function optimally. An air conditioner will have fluctuating pressures even with the minutest bit of air or moisture.


One of the most common reasons air or moisture contamination in your car’s AC system happens is the use of an at-home charging kit. This causes an accidental introduction of air into the system. 


Excess moisture can also harm the desiccant in the system’s receiver/dryer or accumulator.


  1. Defective Compressor

If oil-deprived, a compressor—which pressurizes the refrigerant in an air conditioning system—can swiftly fail. When this happens, all cooling stops immediately, and the interior temperature of the automobile rises.


After encountering an internal air conditioner compressor failure, it is also recommended to flush the remaining air conditioning system.


Ways to Prevent Car Air Conditioning Problems

Below are some practical tips on how to prevent problems to your car’s AC system:

  1. Turn on your air conditioner for approximately 10 minutes once a week. 

You must turn on your car’s air conditioning unit for roughly 10 minutes to keep the compressor operating effectively and maintain the gas pressure. Ensure it is on its highest fan speed and cooling setting as you perform this.

  1. Run defrost mode for 5 to 10 minutes.

Running your automobile’s air conditioning system in defrost mode can help eliminate extra moisture that might cause unpleasant odors and avoid mildew.

  1. Use your car’s air conditioner in the winter.

One of the primary purposes of an air conditioner is to eliminate humidity from your car’s interior. It works well, especially when you must clear the fog from your windshield to improve your vision.

  1. Recharge your AC system.

Refill the gas and lubricant in your cooling system every two years.

  1. Have your air conditioner fully serviced.

Early detection of air conditioning system damage or leak can keep you and everyone in your car cool and worry-free while saving you bucks and time. Have your local auto repair no credit check financing shop, check your AC system.

Final Thoughts


Hawaiian summer heat can rise at any level, so keeping your air conditioning at its peak performance is essential. If your car AC is not blowing cold air or is not functioning as it should, visit us at Car Geeks. Our ASE-certified mechanics will do a complete diagnostic test, let you know of any underlying issues with your car AC, and fix the problem in no time.


Call us at (808) 201-6880 or book an appointment. We are open from Mondays to Fridays, 8:00 AM to 5:00 PM.

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