how to wire a AC pressure switch?
 

I received a new receiver drier today for my 1983-911SC and I was surprised it had a high pressure cut off switch mounted to it.Seeing that my car does not have one of these how do I wire this in?I have a Sanden # 507 compressor.The switch on the drier has 2 male spade terminals,they are not marked for polarity but I assume one is ground and the other is positive?I believe I have made up my mind to use Duracool or similiar R12 replacement refrigerant,do I have to wire in the pressure switch?Any help is appreciated.Thanks

They are neither polarity. It is either normall open or normally closed. Test with a voltmeter. Probably, hopefully normally closed. Then, at high pressure, it will open. In that case you can use it to interupt power to the compressor clutch relay coil. Where did you buy it?

Arizona Mobile Air is where I bought it.If I am understanding you correctly I would run a jumper wire from the compressor wire that activates the clutch to the switch and then back?To complete a loop?

The switch would be wired in series; to the compressor clutch '+'

I have one wire going to my compressor so that is the + correct?So it sounds like I would disconnect this wire,connect it to the switch and then run off the other terminal off the switch back to the compressor?That actually makes sense !!

Assuming that the switch is normally closed, you are correct. Because the compressor cycling is determined by evaporator temperature in most of these cars, and the evaporator is in the trunk, you should find the compressor relay somewhere in the trunk near the evaporator. You should interupt the clutch circuit there rather than run a wire to the back of the car.