Why Are the Brake Lights Always On?
2 Answers
The reasons for the brake lights staying on continuously are: damaged brake switch, worn or aged brake pads, faulty tail light bulb, insufficient brake fluid, or ABS sensor malfunction. It is recommended to inspect these five aspects thoroughly. The brake lights are directly powered by the battery and will illuminate whenever the brake pedal is pressed, regardless of whether the car key is removed or not. Depending on the vehicle model, the brake light switch serves several key functions: 1. The most common type of brake light switch sends electrical signals to trigger related systems or control the power supply to the brake lights; 2. It works in conjunction with the ABS, EBD, or other braking and stability control systems to ensure coordinated operation.
A couple of days ago, I encountered a car owner asking about this issue - the rear brake lights staying on constantly, which is actually a pretty common problem. Usually, it's caused by a faulty brake light switch, either worn out or misadjusted, keeping the circuit continuously powered. I've seen this many times at the repair shop where the switch gets stuck when it should disengage during braking, resulting in permanently illuminated lights. It could also be due to a wiring short circuit, aged wires grounding out, or rarely, a blown fuse. Don't ignore this issue - constantly lit lights drain the battery (your car might not start overnight), and worse, following drivers may misinterpret your braking status, increasing accident risks. My advice: take it to a professional shop to inspect the switch. A replacement only costs a few dozen bucks - don't attempt DIY fixes that might damage the electrical system.
