Common Problems with the AC unit
Air or Moisture in the System
The system shouldn't be contaminated with air or moisture. If it is, it won't be able to work in an efficient manner. This is because, air tends to reduce the cooling https://www.championac.com/ capability of the AC, whereas moisture freezes and forms ice, which may choke up several parts of the system. The presence of air and moisture may be a result of leakages in the system, or missing out to vacuum purge the system prior to recharging it with a refrigerant.
Low Refrigerant Level
The AC needs a specific amount of refrigerant to work in an efficient manner. If the refrigerant is lower than the required level, the AC obviously will not provide cooling at its fullest.
Dirty Condenser
The condenser is a part situated in front of the radiator, which is responsible for cooling the high-pressure refrigerant's vapor that comes out of the compressor. If any kind of dirt is present in the condenser, it would lead to a blockage to the airflow, which would then provide no cooling. In such a case, cleaning the condenser would certainly resolve the problem.
Clogging
There are chances of the tube or metering wall that lets the flow of refrigerant to the evaporator to be clogged by debris. This obstructs the free flow of the refrigerant to the evaporator, resulting in a low level of cooling. It may also damage the inner parts of the system, which run smoothly due to the refrigerant.
Mechanical Complications
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There are possibilities of some mechanical problems, such as a faulty compressor clutch, defunct pressure switches, valve not working properly, and malfunctioning of the compressor. Any of the above problems need to be diagnosed and addressed by a skilled technician.
Solutions
Step 1
If the AC doesn't seem to work, the first step would be to check if the refrigerant is leaking out. Leaks are generally easy to find, but are very hard to be fixed. To check from where the refrigerant is leaking, you may get a fluorescent dye from a car accessories shop, and put it in the system by referring to the instruction on the can.
Step 2
While the car's engine is on, lift the hood and check if the compressor works. You also need to ensure that the compressor's clutch functions properly after switching on the AC. Check if anything needs to be replaced; such as switches, fuses, wires, fan belt, or the seal in the compressor. You need to check if the oil in the compressor is contaminated. If it is, flush the system to remove the old oil, put new oil, and then check if the AC works.
Step 3
You may even need to clean the condenser by using a good quality flushing agent, which would vaporize quickly without leaving residue in the system. If the condenser is used for many years and is giving frequent problems, it's time to replace it. For proper working of the AC system, it's recommended to periodically replace the accumulators, receiver driers, and the expansion valve.
I'm sure you must have got a basic idea about fixing car AC systems. If you want to repair the system totally, you might need to get the whole system replaced from a reputed car technician.
