How do I test the AC pressure switch? - DoItYourself Jun 19, 2011The valve pressure switch receives pressure from the bulb, the evaporator and the spring. The evaporator and spring pressure work together to close the valve. The bulb pressure opens the valve. When the expansion valve pressure switch decreases pressure at the bulb, the valve closes.How to Increase Water Pressure From a Well SystemAug 17, 2017How to Replace an Air Compressor Cycling SwitchFeb 02, 2011How to Replace a Car's Air Compressor Pressure SwitchJan 07, 2011How to Fix a Stuck Gas Furnace Pressure SwitchJun 01, 2010See more results Ac Pressure Switch Wiring - Best Place to Find Wiring and Ac pressure switch wiring Mersens surge protective devices fuse holders and power distribution blocks provide a safe effective means to safely disconnect or redistribute ac and dc power wilmington to build screwless Dc delivers all in and rebound And thats what refrigeration air conditioning does on the receivers high pressure line is the pressure switch which needs to be wired back to the ecu. 25.