So This had me beat and I thought maybe it happened to somebody else, The turn signals in my 04 sierra 1500 started fritzing out. Ive replaced the flasher relay and several bulbs, checked the fuses. All the lights work on the truck as intended except now, when I hit my brakes the turn signal rapid-fire blinks in the front and shuts off in the rear..let go of the brake and the turn signal works perfect. Any ideas??