What are the causes of brake light failure?

[LeCarter]

Brake light failure can be caused by: 1. Brake system failure due to severe oil shortage caused by worn brake fluid pipes; 2. Low oil level in the brake fluid reservoir leading to failure of the float-type sensor; 3. Severe wear of brake pads and breakage of pre-embedded wires; 4. Short circuit in the brake warning system and vapor generation in the brake fluid pipes. The brake system is a series of specialized devices that can forcibly reduce the speed of a vehicle. The brake system mainly consists of four parts: energy supply device, control device, transmission device, and brake. The main functions of the brake system are to decelerate or even stop a moving vehicle, maintain a stable speed for a vehicle going downhill, and keep a stationary vehicle from moving.

[HadleyLee]

There are quite a few reasons for brake light failure. I've encountered it several times myself, and to summarize, the most common issue is a burnt-out bulb. Fuse blowouts also happen frequently, especially when a short circuit causes excessive current. Poor wiring connections, such as loose or corroded plugs, can lead to poor contact over time. If the brake switch fails, the light naturally won't come on when you press the brake. Additionally, faults in relays or control modules are more complex, especially in modern cars. Don't take brake light failure lightly—first, check the bulb and fuse yourself. Try replacing the bulb; the fuse box is easy to locate in the engine bay, and you can find the corresponding diagram in the manual. If you can't fix it yourself, seek professional help immediately, as this light is crucial for road safety. Others won't see your braking intention, increasing the risk of rear-end collisions, especially at night. Make it a habit to have a friend check if the lights are on every time you start the car.

[SanCali]

I've been driving for many years, and the most common reason for brake light failure is the bulb burning out. It's quite common for the filament to break after prolonged use. Blown fuses are also a frequent issue—they melt to protect the entire system if there's a sudden surge in current. Wiring problems like short circuits or breaks can also be culprits, such as when cables age and fray or get chewed up by rodents. If the brake light switch fails, it won't detect the pedal press and won't activate the light. And if the bulb socket is oxidized or deformed, it won't make proper contact, leaving the bulb inactive.

If you notice your brake lights aren't working, don't panic. Start with the simplest checks: open the trunk to see if the bulb has blackened, then try replacing it with a new one. Next, check the fuse for signs of burning—replacing it is cheap and easy. If that doesn't fix the issue, you might be dealing with a faulty switch or a bigger electrical problem.

Though small, these lights are crucial. If they go out while driving, immediately turn on your hazard lights and pull over to avoid being rear-ended.

[LeDominic]

Brake light failures are usually caused by bulb damage, as bulbs are prone to burn out after prolonged use; a blown fuse is a protective mechanism against excessive current; wiring issues such as short circuits or poor contact; a failed brake switch can also cause the light to stay off. I believe the most crucial thing is to act promptly because when brake lights go out, other drivers can't see you slowing down, significantly increasing the risk of rear-end collisions. Start by checking yourself: see if the bulb is burnt out (blackened), buy a new one and replace it; locate the fuse in the box (refer to the manual for its position) and replace it; if the switch is faulty (located near the brake pedal), you might need to disassemble and repair it. If you can't handle it, don't delay—take it to a repair shop. Safe driving comes first.