escort a/c ACP high pressure switch

I have a 1995 escort wagon with the 1.9 litre engine. I can`t find any details on a switch/ control on the high pressure side of the system.It is mounted upside down and has 4 wires going to it near the radiator and condensor at the top.I believe it is called a ACP switch (air conditioning pressure switch).
What does it do and what do each of the wires do?

hoping someone knows.