Australia Lists


31 Aug

Common Errors in Car’s Air Conditioning System

It is no doubt that the air conditioning system is one of the most important features in the car that enhance your driving experience. If there is a problem with the air conditioner, it is really easy to spot as the air is not cool enough or the inside of the car is so stuffy. There are many errors as well as reasons that could lead to these errors in the air conditioning system. Knowing about what will help you maintain your air conditioner at the best condition.


First, to understand about common errors in a car air conditioning system, let’s see how they work:

Basic Operating System:

Very simple, the air conditioning system in car functions like any refrigerator- it transfers the heat from outside the car to the outside of it.

There are two main sides in an air conditioner: the refrigeration side and electrical side.

The refrigeration side has a compressor to circulate the refrigerant, which carries heat. Heat is removed from the car by the condenser.

The electrical side has expansion valve to put down the pressure liquid in the refrigerant liquid and help the liquid flow. Evaporator helps to transfer heat to the refrigerant. The receiver will help remove contaminants as well as cleaning the air in your car.

Here are some common errors with the main parts of an air conditioning system:

  1. Car air conditioner problems:

When you set the temperature to the lowest degrees but still feel cool and not cold, this is when you need to check for electrical air conditioner problems.

Compressor: You can check if the compressor is running or not when you turn on the system. If it is not turning on, sure the problem with the car air conditioning is here. You can use a digital voltmeter to test if the power is running through the compressor. If not, the connection is bad between compressors clutches or the clutch coil is detected. There are also several reasons for the compressor to have no current. It is maybe because of the cycle switch cutting the power because of low internal pressure. Or there is any failure in the switch itself.


Metal contamination caused by compressor fail is the worst problem. Metal pieces could get into all parts of the air conditioning system such as a condenser, hoses, and receiver, and contaminate the system.

This problem could go on and on forever if you replace new compressor but do not clean away all the metal, even a single small-like-particle piece. It will get its way back to the new compressor and destroy it. The air conditioning system is damaged again.

Refrigerant: If you touch the outlet tube and the inlet tube and they seem to have the same temperature, it means that the system has a low level of refrigerant.  This is the most common error for the temperature inside the car not to be cool enough.

You can also check the refrigerant by using a refrigeration thermometer.

Do not jump to the conclusion that your refrigerant is running low on oil and simply add refrigerant to the system. Overcharging your refrigerant will cause pressure in your car to rise up. You need to check if there is any leak first.

  1. Electrical Side Problem:

Condenser fan: if a condenser fan is not working properly, it also could make your car not cold enough. The most common problem is that a condenser fan cannot circulate the intended amount of air, making the pressure rise sharply. There are 3 things you need to inspect in your condenser car: if it can circulate air, how it runs and simply whether it can turn on. Moving too slowly, condenser fan will also raise the problems.

Check if there are any debris or bugs and dirt in the condenser fan.

Cabin air filter or evaporator core: Cabin air filter and evaporator core help to eliminate contaminations and clean the air in your cars. However, if they are clogged, airflow cannot get through. Lack of air flow also prevents the refrigerant to fully function.  Look for any debris, dirt or any kinds of substance that can get into the cabin air filter and evaporator core such as leaves or bugs and insects. Small substances like mold or mildew when to accumulate could also block the evaporator core.

  1. Air Conditioner Leaks:

One of the most common and serious errors is leaking oil can be leaked out of the hose. This will result in the low refrigerant. Because hoses are made from rubber and over time, this material will become loose and not elastic anymore. Finally, they will break down and let Freon get into the system.


Besides causing low levels of refrigerant, oil leak can cause problems to the condensers too. Condensers are prone to an oil leak and battery acid so if oil and battery acid could reach the condensers causing them to be wet and melt away. If Freon can get into the system, there will be moisture in the air creating corrosive acid as well. If the receiver is not working, the problem will be worse.

When your car is hot, it is may be because the evaporator cores have leakage as well.

  • How You Know There Is A Leak:

A leak from the system could be spotted with eyes. You will see traces of leaked oil on the surface. Have a look at all the hoses, especially the ones near the connections. If you could find a trace or residue of oil, it means there is an oil leak.

You can also apply the inspected areas with a mixture of soap and water. If there is any leak, the bubble will appear.

You can also use the method of using fluorescent dye to spot leaks, especially small leaks in the system. The fluorescent dye cannot be seen with naked eyes; you need to use special goggles and flashlights. Under the light, you will see the leak with yellow color.

For an area which is hidden under other parts of the car, it is quite hard to reach and check for leaks, such as evaporator. In this case, it is best to use electronic leak detectors. These devices are quite expensive but come very handy when you cannot find leaks using other methods.

If you think there are leaks in your air conditioner system are you refrigerant is running low on oil, do not add extra oil yourself, you may over pour it and destroy the system easily. If the system is an overcharged, the accumulator will also outflow.

Also, leaks in the air conditioner cannot be fixed with sealer so if anyone suggests you buy it, just say No.

  1. Other Common Errors:

There is an inconvenient smell coming from the air conditioning system and you can smell it all over your car:  the reason for it is because of the old cabin filter which is now filled with dirt and small dead insect (you never know) causing its odor. Another reason is coming from the evaporator. When there is water or moisture, especially when the drain is locked, will develop mold in the evaporator, causing a moldy smell as well.

You hear noise coming from the air conditioner: Make sure it is not the noise showing the compressor is working. Otherwise, noise can come from refrigerant whose pressure is too high or hose and other parts are not tight and rattle against each other.

First, your car is cool but then it starts to get warmer: There are various reasons for that:

  • The expansion valve: As mentioned above, expansion vale can be blocked by dirt, leaves, and small insects. In this case, the refrigerant cannot get into the expansion vale. First, the amount is small so it can get through, your car is cool. But then just like water running down a clogged hole, the refrigerant is kept outside the evaporator, and the air inside your car become hot.
  • Compressor clutch: Again, compressor clutch if not working properly, cannot help your compressor to maintain the needed pressure causing hot air.
  • Fuse: Fuse shorting out could also cause the problem.

Overall, there are many reasons why the air conditioning system is not working. At any case, you should not fix the problems yourself or the problems may be worse. It is best you consult expert technicians and take your car to one of the best car services in town. After all air conditioning system is very dedicated and needs the best care to run properly and smoothly.