Diagnosing the compressor is fast. First- check for burnt compressor terminals or burnt O.L. Second- ohm the windings, with cool compressssor, to be sure the internal O.L. is closed.. c-r ohms plus c-s ohms = r-s ohms? If not, kiss the compressor goodbye. Third- There IS a bypass tool called an Annie. Unplug the comp. wires and hook up the Annie, which has manual switches and the capacitors inside, and hit the on and then start button. If it still doesn't start... kiss the compressor goodbye. If it starts, use the volt meter to follow the path to the comp terminals to see whats wrong.
It sound like you know what you're doing. You can do it all with a vom and amp-probe but an Annie makes it fast. I built an Annie in school, mid 70s, for extra points. I bought an Amprobe, vom and a cap. tester as soon as I was out of trade school and they've been indispensable.
Your relay looks like a potential relay and pickup/dropout voltages are critical but who knows what's on these cheap, sh!tty units! Craig
