Originally Posted by dieselnut
my vehicle is completely stripped of all the "factory" electrical stuff. everything is on switches now, the "brake" switch has a normaly closed switch but when you press down on the brake pedal it goes to an open switch, any reason why i shouldnt wire my tcc through that switch?
Are you sure about that? Usually the brake light switch is NC. When the pedal is up, not being pressed, the switch is open, depressed, no brake lights. When you press the brake pedal the switch closes and lights the brake lights. Just the opposite of what you need for the TCC. That is why the relay is used.