Dual-Pressure Switch
WARNING: This page is about a different car, the 2001 Subaru Impreza and 2000 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.
Dual-pressure switch is located in high-pressure line. Switch consists of a diaphragm, diaphragm springs, pin and 2 contact points. One contact point activates when internal pressure is too low or too high. The other contact point controls operation of sub (condenser) fan.