QuestionQUESTION: I have a 1956 Ford F100, Brake light has started coming on while driving. I have replaced the switch, bled the lines after putting in the switch. The light works fine while sitting still and i apply the brake, it comes on and goes off as it should. The problem is that it comes on when i start moving down the road. I almost appears that the wheels turning is putting pressure in the master cylinder to activate the switch.
ANSWER: Are your sure this is not your fluid level idiot light? They go bad often and are set off by motion.
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QUESTION: I am talking about the brake lights at the rear of the truck, not a light on the dash.
AnswerSounds like the switch actuator is set too loose. It should be adjustable. Barring that, you have a short, but unlikely, as the brake light switch would handle it.
In a very rare case, it is possible the blinker or flasher rheastat can do this. Simple to check, just unplug and test drive it.
