Get one of these and put a cord on it so you can remove the relay and directly connect up the compressor to see if it will run. It has 3 compressor terminals on it and directions are on it. Keep it in your tools. You can use these to take the place of the cap,the relay, and the overload; all of that is in the hard start pack. I have one for air conditioners too. The HS650 is designed to piggyback on top of the original capacitor, sometime called a torque multiplier. Click pic to enlarge In the picture is an HS410 primarily use for 1/4th horsepower and 1/3rd HP compressors. They make a smaller one that is used for 1/5th HP compressor to 1/12th HP compressors for freezers and water fountains.