AC Pressure Switch ?

[70GMCer]

Still gathering parts to restore my AC in the 83.

Regarding the "Pressure Switch"....I know there is a difference between the R12 & R134 switches.

But, I see on the original R12 switch, there is what looks like an adjustment screw. (see pic)

Has anyone adjusted this switch to work with the R134 conversion & how was it adjusted?

Correct me if I'm wrong, but I believe that the pressure switch would have to be adjusted to a lower setting.....

Or....make it easy......is there a direct replacement for this switch?

One more thing is that the AC system on my truck had been previously changed over to R134.

So, that switch might have been already adjusted..