(glspage @ Oct. 10 2006,5:51)
QUOTE
........... believe there's a short somewhere. Turn on compressor and breaker blows. Keep thermostat off and has power and a fan blows.
You have narrowed the problem to the wire feeding the compressor or the lower fan motor. 
        First remove the cover from the compressor and you'll probably find a  pinched  or bare wire. 
       Wiring is being discussed in another post, change those wires before you pay a pro to come out and do it for you.