Burned $220 on a used compressor off Marketplace for a fridge job
Drove out to a guy's garage in Mesa to grab it, hooked it up, and it wouldn't pull past 30 psi, so I had to eat the cost and buy new anyway. Man said 'it ran fine last time I used it' which I guess meant 2019. Anyone got a trick for testing these before you hand over cash?
Bring a set of gauges and a multimeter, that is really the only way to know before you pay. Hook the gauges up right there in his driveway and watch how fast it pulls down, a good one will hit vacuum in a minute or two. Put the meter on the windings too, check for ohms and make sure nothing is grounded out to the shell. If the guy won't let you test it, that is your answer right there, just walk. Learned that the hard way myself after getting burned on a used one that "worked great".