If that's with the compressor leads unplugged, that's good. Run winding ohms + start winding ohms = total ohms. So, R -W is the ends of the S and R windings, with the highest Ohms, so that means Bk is the common terminal.... between start and run windings. Bk-R is start winding cuz it's higher Ohms than run. Bk-W is the run winding... Bk is 120v and W is neutral during operation. Make sure all terminals to gnd., ohm infinite. This only means the windings ohm good and the internal OL is closed... could still have a locked or sticky rotor.
Unless things changed (got cheaper) there's usually a small round, black external OL under the terminal cover and it's in the common (120v) wire. Of coarse, it needs to ohm closed. The run cap. is permanently connected between S and R terminals and it's built to take the constant load. If replacing, keep the run cap. Mf within 10% but you can go up on voltage but not down. If you have a start cap. it will also be between S and R but a relay, current type, PTC (positive temperature coefficient) type or potential type is required to open the start cap. circuit when the rotor starts spinning cuz the start cap isn't built to stand an extended load... they will go bang, in short order! An amp clamp is SUPER useful to see what the start winding is doing, on startup. Put the clamp on the start cap circuit and you better see the amps jump and then immediately quit. If that doesn't happen, something is open in that circuit... it's that simple.
So, for the acid test... put your voltmeter on the common and run terminals and you will see the voltage as soon as all controls close and watch the amp clamp to see start currant... it will draw currant if the start cap. and relay are good. Then put the amp clamp on the common wire to see the total amps the comp. is drawing. If all is still going well, move the amp clamp to the run cap. circuit and you can see what the run winding is drawing... and it will be drawing some currant if the run cap. is good
If necessary, use heavy gauge jumpers to bypass the T stat and other controls so you can successfully isolate and check the compressor.
Don't run the compressor very long w/o the fan motor running.
PSC, permanent split capacitor, meaning split phase - a start and a run winding, and the run cap is permanently connected to S and R. The start cap and relay give the rotor an extra kick but the start cap. drops out nearly instantly. IIRC, the start caps on these tiny things are only about 40-50 Mf and are uncommon. If the compressor is cool and been off for a long time, so the pressures are equalized on the top and bottom of the piston, they will usually start w/o the start cap. unless the rotor is sticky.
They're really fast tests, once you've done them a few times.
Something I just found
https://abrwholesalers.com/blog/how-to-check-a-single-phase-compressor/
