What kind of car is it?
Late 80's-early 90's GM vehicles often have the wiring harness from the turn/hazard/horn/cruise control etc. draped over the top of the steering column. After 100,000+ miles of turning back and forth the steering shaft can rub away the insulation and give you a short. I had to rip apart the entire dash on my '88 Iroc-Z before I discovered this.
My 87 trans am did the same think. It was a shorted wire. You pushed the brake pedal / the fuse blew / no brake lights. I have the entire interior out and the entire dash, had to trace almost every wire.