My fan on my out side unit run and I can hear the compressor try to kick on for about 3 sec then shuts off. I have 240 volts on both sides for the contactor! Please help!

Same problem on mine. Check for short to ground (scratch test) on the compressor to see if the compressor is fried. In my case, I had undersized ducting causing a lack of air passing across the coil, thus liquid refrigerant returning to the compressor and causing damage. I'm replacing the compressor myself since I have the certification. I'm upsizing the ductwork also so this won't be a problem again.