Brake Lights

Hey guys, I'm new to the scene, and I already have a question for the experts...
Just bought a '92 lude and just found out i bought it with no working brake lights! Reverse, signal and parking lights work fine, checked all bulbs back there. I keep blowing fuses every time i start. I took it to my local dealership, and man, they didnt know what the problem was. They said they were going to charge me some cash to do a wire trace. Big $$$ from a dealership. Anyone have any ideas I can try, or a good place to take it for repair other than an expensive dealership in Calgary Alberta?