a/c pressure switch

Does anybody know if the switch on the a/c accumulator (aka receiver/drier) is a high pressure or low pressure switch? This switch is also called a a/c clutch cycling switch. Also, do I have to deplete the a/c system prior to removing the switch?
This switch is why my a/c compressor clutch is not engaging.
Thanks.

The vehicle is a 1992 B2200 w/ a 2.2L 2 BL.

I would use the original settings as far as pressure. it will differ depending on the outside temp in front of the condenser or a/c accumulator.