I have check wiring at condenser unit out side, compresor and fan will come on and work if you push the button in the center of the relay and hold it but it will go off as soon as you release it.

Sounds like you ar talking about the contactor relay - which is a common problem if the unit is a few years old. Either the contactor points have deteriorated and are not making a good connection or the contactor is not being activated. In either case, you are dealing with potentially lethal voltages and you should have a local professional evaluate and repair your problem for you.

I agree with the answer jgj6331 gave you unless have a good knowledge of electricity. Plus you will have to have a voltage meter to trace down the problem.

Q:My A/C compressor and fan not coming on I have checked wiring at condenser unit out side, compresor and fan will come on and work if I push the button in the center of the relay and hold it but it will go off as soon as I release it. Please help me!!