A/C Pressure Switch - Low AND High?

[NickyV]

The A/C rabbit hole just keeps getting deeper, but I'm so close! I'm pretty sure I've figured out how to properly reconstruct the dealer-install harness for my 1987 2.5L. I will be posting about that soon in my build thread.

 

Anyway, this morning I was realizing I needed to order one of those two-prong low-pressure switches (the dryer I bought did not come with one). And then I stumbled upon this post from 2021 where @Torq_Shep and others were speculating that the low pressure switch failed due to HIGH pressure and caused a refrigerant leak.

 

 

It seems earlier MJs like mine never had a high pressure switch, but I'm thinking I could probably add one? I'd just need to wire it properly (probably by adding yet another relay (I'm already up to three, because I'm adding an e-fan and I gave up on trying to figure out how to recreate the fan diode assembly).

Has anyone done this? I'm adding A/C from a heat-only, so I'm in a good place to add customizations. The system hasn't been installed or pressurized yet. Would it be as simple as finding an adapter that goes somewhere in the high-pressure line and the wiring up a relay system so that the "A/C Request" input is cut if either the low or the high switch trips?