Simple basic about Automotive A/C - Part 3

Welcome back to this part 3 of basic a/c. On last 2 post, i have talk about compressor, clutch, condenser, and condenser fan. So in this post, i will talk Pressure Switch, Service Port, and Filter drier.


This is A/C Pressure Switch used in car a/c. This switch comes in different design and shape, but all with same principle.

So, the pressure switch is use in a/c to take reading of refrigerant pressure inside the a/c system. It is use to regulate of how much pressure the system can take, and if the pressure is below or higher than the system can take, then the system will shut off the compressor to prevent major parts failure. This switch usually is placed at High Side of the a/c system, depends on system design, some car will come with two switch, one in Low Side, and one in High side.


This are the several kind of Filter Drier that can be found in cars. Deepening on system design, the filter will have different shape.

Filter Drier is use in a/c as an humid absorbent. This filter contain desiccant that can absorb small amount of water/vapor that may get into the a/c system during installation and service. A/C system required a dry condition for it to function properly. If there is too much water/vapor inside the system, the refrigerant will freeze up and thus blocking of refrigerant flow will happen.


Some of the service port that can be found in car a/c. 

Service Port is use by a/c technician to plug a pressure meter to take reading of the internal refrigerant pressure. This port is very vital because it provide access to top up, recharge and also to recover the refrigerant in any a/c service.

This three parts will have its dedicated post in future. Now i will just focus on basic understanding of the car a/c.Stay tune for my last part.