As we all know when it comes to electrical...It could be anything.
Of course you check your fuses,bulbs first...Then if no luck, check
your switch or wire at brake pedal. Last and wierd, but been found to be
true..that darn Hazzard switch. Before you get deep in a wire mess, it would not hurt to play with the hazzard switch while a second person checks to see if that does the trick. One guy said it was grease getting on the hazzard switch..it makes the contacts not work right...who knows..GOOD LUCK