Take a look at this:
http://www.thatquailplace.com/smf/index.php?topic=3831.0I had posted a link in this thread that directs you to
www.gqfmfg.com. They have some wiring diagrams online for their incubators in which some have dual stats, don't know if it will help you any or not.
If you're familiar with electric you should be able to track down the problem with an ohm meter, start at the fuse block and start unhooking things until the "short" goes away......then you'll see what is causing the problem.
Good Luck! .....and....