Why Are My Brake Lights Staying On?
Brake lights are part of the tail light and illuminate when the brake pedal is pressed. If your brake lights are staying on with the vehicle off, the most common cause is a broken brake light switch or brake light switch stopper.
How to Fix the Brake Light Switch Stopper
Inspect the Stopper and Brake Light Switch: Underneath the dash, locate the brake light switch near the top of the pedal. Check for a stopper in the brake pedal on the opposite side of the brake light switch. If the stopper is there, confirm the switch is depressing all the way and is not faulty (the brake lights will turn off when the switch is depressed), otherwise the entire brake light switch may need to be replaced.
Scan the Floor for the Stopper: If the stopper is missing, scan the floor for the plastic stopper—it may have broken into pieces.
Replace the Stopper: If the stopper is broken, replace it with a new one or an item of similar width like a bolt. Do not loosen the pedal, and confirm that the replacement item can depress the brake light switch.
Disconnect the Power Source: If the stopper is not the problem, disconnect the negative battery terminal (as long as the hood latch is not electric) or the brake light fuse to prevent the battery from draining.