I think the comp is NG, assuming it actually has refrigerant still inside

what is your country

I think any sniffer from a so-called big box store would do for the random user

You may be correct. The hi side pressure you give leans toward that. However, you have done the testing at 650RPM. We test auto AC by having the RPM at 1500-1800. Repeat your testing at that RPM. A compressor does very little work, if any, at such a low RPM Also, how many miles on the car? You are l...

Agree 100%

Are you saying 11.7 ohms for the compressor switch or the clutch coil?
I have never seen a clutch coil at more than 4 ohms, and 11.7 ohms for any switch seems high to me

"I have seen a lot of older systems that only have a trinary switch on the reciever dryer"

A trinary switch includes a LPCO:

"The AC trinary switch has three functions: high pressure protection, low-pressure protection, and fan control"

Try the automotive stores. Truth is, as you know, everyone is getting out of the 134 business, thanks to the EPA. EPA won't even let ppl sell refrigerant on eBay any more! These are stocks that were produced legally! Stock up when you can and be careful of how you vote! You need an administration th...

I am late to the party here, but I think from your original post you are mixing up the direction of flow, and that is causing confusion in the replies. The #8 line on your existing evap is not a return line, it is a supply line...this is the high pressure liquid input to the evap. The #10 is the vap...

"so I added some and will wait to see if it holds"

Hopefully what you added did not have sealer in it. Those fancy cans at the parts store with the short hose and low pressure gauge have sealer, and will gum up your system. And those gauges are notoriously inaccurate

I expect the sensor on top of the accumulator is the LPCO. I'd replace that, it most likely has a shrader underneath it so you don't lose charge when replacing it. You don't want to lose the action of the LPCO, since that protects you in case of a refrigerant leak. A system with insufficient refrige...

One thing that comes to mind is a faulty LPCO that lets it stay running, although that would not account for the comp running when not turned on, unless as Cusser mentioned