Where is the probe going for the preset thermostat? Adjust the probe to the correct position and you should cycle the compressor. I just checked and its clamped on the line with a hose clamp on the accumulator and had about 1/4 inch thick of cork tape and about 3" of the line. Wouldn't my syst...

Actually, they're both electrical, just that the existing sensor takes its signal from evaporator temperature and the other from evaporator pressure. If the R-4 is cycling okay and you're getting nice cool vent temps, I would leave it alone. Its still set up for r12 and right now and it doesn't cyc...

So I guess no one knows if any benefit to removing the thermostatic and go with the electric cycling switch? I'll just leave it as is while on r12.

Making new threads tends to leave gaps... https://www.autoacforum.com/viewtopic.php?t=14057 The previous one was about another subject and I added this question to it. Was no longer getting any replies/ and no one answered that part. So started this one with the subject line pointing to my question...

Dougflas wrote: ↑Thu Jul 22, 2021 4:32 am Photos would help answer your question. Is the updated POA an eliminator type

I had photos in my other post and added this comment to it but got no replies on it so I went to start a new post with the subject line pertaining to it anyway here is the pics... [/attachment]

Since my 73 Nova with R12 has a newer cycling clutch compressor (R4) and a updated POA valve would it be best to remove the thermostatic cycling switch and install a electric cycling clutch switch in the POA or just keep as is?

bohica2xo wrote: ↑Mon Jul 19, 2021 7:51 am I would just stay with 134a in that hybrid system

Guess i wasn't awake yet as I meant to change it to r134a as right now it is r12.

So I have a updated POA and using a clutch cycling thermostatic switch in place of the electrical switch that is usually mounted on the POA. Now that I know what I have guess its about time to start troubleshooting. Now I wonder since I already have most things in place for it if I just convert to r...

That is an R4. The actual part numbers are in the top part of the picture. You can run that compressor without a POA valve, but you will need either an evaporator temperature sensor or a cycling switch on the low side. Not clear where the TXV sensing bulb is located in that picture. Hopefully it is...

That is a piece of pipe. Sold as an upgrade for a precision control valve. Depending on what compressor you have it may or may not turn the evaporator in to a block of ice on a long drive. Your compressor number comes up as a fan clutch for me. Which compressor do you have? its a ACDelco 4849 here ...