A brake switch, commonly called a brake light switch, is connected to the brake pedal of a vehicle. It turns the brake lights on when the brake is depressed and off when the pedal is released. A faulty brake switch will result in the brake lights not working, which may cause an accident.
When the brake lights on a vehicle stop working, the first thing a mechanic will check is the brake switch and the two wires leading from the switch. Because the switch only has two wires, it can be easily replaced by many drivers with only a little mechanical aptitude and a few basic tools.