Have an old Sears Coldspot 17 upright freezer that won’t get cold. Replaced the starting relay but still doesn’t run (except the fan and light). When it’s plugged in, about every 30 seconds, the overload relay clicks and the compressor hums for about 3 seconds, Then the overload capacitor clicks loudly, sparks, and the compressor quits humming. 30 seconds later, same things again. Do overload capacitors ever go bad? Could I be that lucky that it’s only the capacitor and not the compressor? Any help would be appreciated.
Your klixon overload is clicking off on high current. Probably compressor failure. If you put an amp probe on it, if the compressor draws very high current, like well over 20 amp, you have a bad compressor.
You can try a 3 n 1 hard start device on it, but you will need to measure which compressor terminals are common, run and start. These devices can only be used on compressors drawing more than 2 amps, usually with R12 refrigerant. Also, if the compressor is drawing excessive current, they could catch on fire!