[cruizin01]

Originally Posted by hatzie

The proper location for a standard LPCO Switch is on the dryer.

The pictures help. I'm a pretty visual person...

The hose from the condenser to the orifice tube in the base of the evaporator is on the high pressure side of the system. That port could be used for a HPCO switch. I usually install them close to the compressor but that location is sufficient for the task and easier to wire. I would add one if you intend to use R134a.

The switch should be wired in series between the LPCO and the compressor clutch.

LPCO is a Normally Open switch that usually closes at @ 25-30PSI.
HPCO is a Normally closed switch that usually opens at @385-425 PSI.

Here's a quick N dirty sketch of the clutch wire with a LPCO & HPCO switch and Snubber diode installed.

Hatzie, Thanks again for all your work. Id like to add the correct switch for future proofing even if I do R12 right now. Any idea on how to find the correct HPCO switch for my line? I ordered a couple LPCO switches in hopes of them at least plugging the hole but would like to have the right switch to wire in.