AC box: what it does and how to troubleshoot it

What is an air condition box?

An air condition box, abbreviated as an ac box, is an automobile system used to cool down the temperature inside the vehicle. The ac box can achieve this by removing the vehicle’s existing heat and moisture, allowing the system to give cool, dry air. The ac box is located in front of the radiator, therefore, getting the name mini-radiator.

What does an alternator do?

During hot weather, the ac box is responsible for giving a cool environment in your vehicle by eliminating heat and humidity. Notably, all the modern vehicles have been fitted with a standard air conditioning system. The typical ac system consists of a compressor, condenser, and evaporator.

The functioning of the ac system requires a refrigerant. The cooling process begins when the compressor powered by the serpentine belt compresses the refrigerant to liquid form. Resultantly, this creates a high-pressure state on the liquid, which is used to drive the liquid from the compressor through the hoses to the condenser.

The operation of the condenser is analogous to that of the radiator. In the condenser, the ac hoses come in contact with the cooler outside air, thereby removing heat from the liquid. Later on, the refrigerant passes through the ac inline filter that removes any dust particles that might be absorbed from the outside air. The cool refrigerant is then passed to the evaporator section through an expansion valve or an orifice tube.

In the evaporator, the low-pressure refrigerant is converted into a gaseous form. This allows the refrigerant to absorb heat from the air that passes through the evaporator fins. The absorbed heat makes the cool air go back to the vehicle’s interior while the refrigerant remains hot and makes its way back to the compressor, where the cyclic process continues.

Can you replace it yourself?

Replacing a faulty ac box yourself is a better and cost-effective option than finding a professional. However, you will need to have some basic knowledge about ac box functioning and repair. Below is a guide on how to replace a faulty ac box;
 Open the hood and locate the ac lines
 Disconnect the battery terminals
 Discharge the ac system to remove the present refrigerant
 Remove lines on the compressors and disconnect the electrical connectors
 Remove and replace the damaged ac lines, o-rings, compressor, condenser or evaporator
 Recharge the ac system with the refrigerant. Be sure to check the ac lines are not leaking.
 Reconnect the battery terminals
 Turn on the ac system and confirm if cold air is coming out of the air duct with the engine running.

Things to know and remember when replacing an ac box

Prior to replacing the ac box, you need to be certain that it is a problem and not any other cooling system component. Therefore, it is necessary to measure the cabin temperature when the ac is on prior to the replacement. The recommended temperature should range from 5°c to 10°c.

Secondly, you need to check the level of the refrigerant on the ac system. Low refrigerant levels cannot effectively cool the car’s interior. This will give you a false perception that the ac is damaged.

The ac lines are then checked for any leaking. You can do this using a UV dye that easily identifies a leak. The leak can be a result of poor sealing or damaged bearing.

Different types/generations/models of the part

The automobile air conditioning system is broadly divided into the expansion valve system and the fixed orifice tube system. The two systems have a similar principle of operation but only differ in the component used to lower the pressure of the refrigerant. For the expansion valve system, the expansion valve is used to lower the pressure, while in the other ac type, the orifice tube is used.

Different subparts of the ac box

The components of the ac box include;
 Compressor. The compressor is used to pressurize the refrigerant to cool air, monitor and control temperature output and move air to the condenser.
 Condenser. The condenser is used to reduce the temperature of the hot compressed refrigerant.
 Expansion valve or orifice tube. This component is dependent on the vehicle’s make. Some have an orifice tube while others have an expansion valve, but both serve the same purpose. They are both used to monitor the temperature and pressure of the ac system and regulate the amount of refrigerant that goes to the evaporator.
 Receiver/ dryer/ or accumulator. A receiver/dryer is used with an expansion valve, while an accumulator is used with an orifice tube. This component is filled with a desiccant that separates liquids from gases. It is also used as a filter for the system.
 Evaporator. It converts the refrigerant from liquid to a gaseous state and simultaneously dissipates heat hence cooling it down.

Identifying issues or symptoms of failure/problems

When the air condition system is about/has failed, the car gives you a lot of signals. To be ahead of the problem, you need to be aware of the failure symptoms. Below are some of the visible signs;
 Insufficient cooling
 Unpleasant smell from air ducts
 Oil leaking
 Engine overheating
 Water seeping inside the cabin
 Strange noise.

Frequently occurring issues with the part

In case you experience a malfunctioning ac system, the possible causes of the problem are;
 A refrigerant leak caused by a faulty 0-ring or bad seal
 A clogged expansion valve or orifice tubing
 Damaged condenser, evaporator or compressor
 Failed blower motor or blower motor resistor.

Normal life time

Even though the ac box is designed to last a lifetime, it can get damaged prematurely. Its approximated lifespan is 10 to 15 years.

Other parts to replace or fix when replacing the air condition box

For optimal performance, you need to replace more than the ac box in the system. The other components that might need replacement are the condenser fan motor, run capacitors, and ac contactor (relay). You can purchase all these parts at autoparts-24.com.

How to make sure you purchase the right part for your exact car

Depending on your car model, you will be able to select the right ac box variant. Notably, you selected the DIY approach since you needed to minimize the replacement cost. You can even lower the running costs further by buying a used part. However, you need to purchase a used OEM ac box to be certain of the compatibility. Any used OEM part can be found at autoparts-24.com

Conclusion

Using a car with a damaged ac box is near an impossible task. Therefore, it is imperative to find a replacement for this part. Keeping in minding price consideration, choosing a used OEM ac box is the ideal option to run down the replacement costs. Luckily, this specific part is readily available at autoparts-24.com