[dmjlambert]

I think it matters what you mean about "updating" the POA valve.

If you are talking about rebuilding the POA valve and recalibrating it to work with R134a, then you would not need to cycle the compressor and that means no binary, hi-lo, or cycling switch. The compressor doesn't cycle.

If you get rid of the POA valve and put in a POA valve eliminator, the POA valve eliminator has 2 terminals on it and you wire that up to interrupt the power going to your compressor, and the compressor cycles. So the wiring would be as shown in the wiring diagram, except you would run the compressor wire to one terminal the POA valve eliminator, and the other terminal on the POA valve eliminator connects to your compressor. That's the way mine is wired. The POA valve eliminator on mine switches the compressor off if the pressure is too high or too low.

My dryer came with a plug that can be removed and a switch to install in that plugged port. I did not use it and Original Air, who sold me my A/C kit, told me I don't need to use that, just wire the POA valve eliminator in-line with the compressor wire.