This air conditioner has a over pressure switch, and a pressure up/down switch. The pressure regulating switch is located on the receiver dryer. The switch on the receiver dryer should be normally closed. If it is open, the compressor will stop, reducing the over pressure condition. This switch has violet and orange/violet wires on it. With the airconditioner off, the contacts should be shorted when checked with an ohmeter. The pressure up/down switch, which is in series with the over pressure cycling switch is normally open. It is located near the high pressure Schrader valve. IT has violet and blue/violet wires. You cannot change these switches without bleeding down the system, and refilling it. Unfortunately, this is not a DIY job. You need special equipment.
The Shrader vavle on the low pressure side is the one on the receiver dryer input.
