I realized (about a month after the fact) that my sprinkler well isn't working. I saw that the breaker was tripped, so I switched it back on, which caused the pump to kick on for a brief moment before tripping the breaker. I tried it a second time (yeah, I know better) and the same thing happened. When I took off the 30/50 switch, I saw that there was burn marks around the housing where it touches the pump motor (gasket was missing, last time I pay somebody to do this stuff), so I bought a new relay and wired it up. It was successful in the way that the breaker no longer tripped, however, now the pump just makes a humming noise but doesn't really seem to kick on. I took off the pressure tank to prime the pump (not sure if that is necessary), but the pump was already full of water. I removed the back cap and I am able to turn the shaft quite easily, so at least it isn't seized up. At this point, the only thing I can think of is the capacitor (pic attached), so I am going to see if I can find one of those, but I am wondering if there is anything else I should check? The pump is 15 yrs old, but it only runs twice a week to water my lawn and like i said, the shaft turns very easily.

Thanks in advance for any help.

 

Welcome to the forums! From what you have described in your analysis, it does appear the cap may be bad. Nothing to lose in replacing it to eliminate it from the equation. Let us know if that solved the problem before we go much further.