Trinary Switches - High Medium Low Pressure switch

Classic Car Air custom made trinary switch.
A trinary switch is used with mechanical AC compressor as a limiting control for the compressor.

1. It detects if the pressure is too high (over heating) or too low (low gas) and switches the compressor off to safe guard it.
2. It uses the medium pressure to control a condenser or thermo fan to cool the condenser core and prevent over heating - through the use of a relay.