Thanks for your help. I am talking about the switch on the receiver/drier in the back of the compartment (#5). According to a diagram in Bentley's 240 service manual, that is the high switch. But whatever it is, that's what I'm referring to. As far as the gauge, it's simply one that came with a can ...

My 1993 240 wagon AC's compressor does not kick on unless I bypass the high pressure switch. Then the AC works great. Nice and cold. it is an R134a system. When running, the freon pressure is about 35psi - pretty good. If I quickly hook up high pressure switch, AC keeps working. When not running, th...