nowhere will the dash light wiring intersect with the brake wire
I can think of one scenario where it will. Power from the brake light switch goes to the brake light bulb but it finds no ground there. It then travels through the tail light filament, back up the tail light wire to the switch, where it is connected to the dash light circuit as well as the headlight circuit.
Clean your tail/brake light bulb and socket and the ground for it.
Edit: OOPS, not so with a task force headlight switch. Sorry for the confusion.
