2002 Hyundai Sonata brake lights stuck on.

Replace both lights bulb

Cars these days have electronic switches connected to the computer system, and they operate simply, until a little glitch shows up. In my case, the brake switch plunger strike pad had disintegrated. This little half inch button goes into a metal pad that presses against the brake switch when the brake is released. The cruise control operates the same, both activated by the brake pedal, both found under the dash. If not this, the switch might be bad. Both found at Advance Auto.

The brake lights work regardless of the ignition switch. There is normally a switch mounted under the dashboard, that presses against the brake pedal hangar. Normally, when you press the brake pedal, this switch loses contact with the hangar, and the brake lights come on. If the switch gets broken or out of adjustment, the brake lights can stay on at all times. This will eventually kill the battery. Readjust or replace the brake light switch.

Could be a stuck brake light switch near the brake pedal.

mcdevito75 here, Are you sure your haedlite switch is off, if it"s on your brake lite will also stay on. However it could be the brake light switch out of adjustment. It"s located on the brake pedal, with your foot behind the brake pedal gently lift up on the brake pedal and see if the brake lights go out if they do or even if they don"t, have yoyr local shop check it out.

Look for a bad ground to the taillights, brake signal is be rerouted from the brake lights to marker lights circuit back to the dash lights and then ground

either the brake light switch is defective or it needs to be adjusted further away from the stop on the brake peddle lever.

switch behind brake pedel is bad , replace switch

If it's just the light that stays on, often that's a sign that your brake fluid is low.

sticking brake light switch at pedal arm