What are the reasons for brake lights not working?
2 Answers
Brake lights not working can be caused by: 1. Damaged brake light bulbs; 2. Malfunctioning brake light switch; 3. Blown fuse. The working principle of the brake light switch is: when the brake pedal is pressed, it pushes down on the brake light switch contact point, completing the brake light circuit and turning on the brake lights. When the brake pedal is released, the switch contact opens, turning off the brake lights. Brake lights are installed at the rear of the vehicle and feature red lenses to enhance light penetration, making it easier for following vehicles to spot the vehicle ahead in low visibility conditions, thereby helping to prevent rear-end collisions.
I've been driving for over twenty years and have encountered brake light failures several times. The most common issues are burnt-out bulbs or blown fuses. Last time, another driver alerted me, and after checking the fuse box, replacing a new one fixed the problem. Another frequent cause is aging wiring leading to poor contact—over time, connectors loosen and cut off power, which can be easily diagnosed with a multimeter. A faulty brake pedal switch is also a major culprit; if it doesn't respond when pressed, the light won't illuminate, but replacing it is simple and inexpensive. Relay damage is another issue, as it disrupts current control and affects the entire system. I recommend thoroughly checking lights during regular maintenance, especially for older vehicles with worn wiring—road safety is no trivial matter, and the liability in a rear-end collision can be significant.
