Also: You should ALWAYS replace the capacitor when you install a new fan.
If the compressor wires aren't burnt, then you can confirm the compressor is the trouble by doing this:
1) Remove power from the furnace. Be 100% sure you've done so - check it with a meter.
2) Remove the wires from the compressor terminals. Isolate them so they don't touch ground anywhere.
3) Turn power back on.
4) Turn the system on at the stat
If the breaker does not trip with the compressor out of the circuit, then you've got a bad compressor. Time to call a reputable HVAC company for assistance.
If the breaker does trip, then the compressor is not at fault. You'd need to remove the other components in a similar fashion to determine the short.
Last edited by scottmcd9999; 08-06-2012 at 06:42 AM.
Reason: remove "NOT" from last sentence