I haven't had a chance to work on it since my last post but you guys are giving me a lot of ideas. I think here's the plan for tonight: I'll disconnect everything from the circuit board including the thermostat wires. I'll only have the 24 volt wires from the transformer connected to it and I'll turn on the power. If the fuse holds, then I'll hook up the thermostat wires. If that doesn't blow the fuse, then I'll connect up the compressor relay wires and see if that's it, and then continue connecting stuff until the fuse blows. I think I will disconnect the wires that go from the compressor relay to the compressor while I am testing so that I don't have the compressor running while the other stuff is not activated. I'll just be testing each 24 volt thing, one at a time. Thanks for all the help so far!