I have replaced the compressor starting device (twice, since we thought the 1st one was bad) overload relay, defrost timer, and the freezer thermostat kit on refrigerator all bought from Appliancepartspro. The compressor ohms out correct and refrigerator runs fine with a Supco 3n1 start capacitor in place of the starting device. As soon as I take off the 3n1 and put on the overload relay or starting device with capacitor the compressor starts only once and then starts clicking and will not start again. I have read several posts not to use the 3n1 for a long period of time due to the strain on the compressor, or overheating of compressor. Any ideas??? Thanks 
Hi.
Most likely the compressor is damaged internally and it takes more power to run it than regular starting devise providing.
In this case you probably should leave the “3in1” in place.
It doesn’t mean that compressor is going to die right away.
You still may have it working for some time.
Simon.
Ok Thanks, Simon. is there any way that the capacitor could not be the correct part for this compressor and that is the reason why it won’t start? for example, the one I have being using is 15uF 210V AC, but I have noticed during my research for this problem that some capacitors for this refrigerator have been a 15uF 220V AC capacitor. Could that 10V difference be enough to not let the compressor start? Do you consider it safe to run a 3n1 on a R-134a compressor, I have not noticed any heat problems or any other problems using the 3n1 for about a week. Thank you for your help
JCrabb
HI.
As I mentioned earlier the “3in1” is you way out at this point.
The 10V difference in the capacitor rating is not important at all.
Simon.