Review of Common Brake Light Problems

Have you ever driven behind somebody whose brake lights weren’t working? It’s a scary situation when all of the sudden the distance between you and the car in front starts to disappear without warning.

Automobiles with brake light problems are like an accident waiting to happen and therefore shouldn’t be driven on the street at all. This article will address common problems with brake lights, including diagnosis of the fuse, brake switch and dealing with burned out bulbs.

Brake Light Switches

The stop lights are turned on and off by a switch that is normally mounted to the brake pedal. The important thing to know about this circuit and what makes it different than others is that power is supplied to the brake switch at all times. This means the keys don’t have to be in the car for the brake lights to work.

On most vehicles, a brake system will have a separate fuse to protect the circuit. This is important if the switch should become stuck in the on position and is draining the vehicle’s battery. In this situation the fuse can be pulled and the vehicle towed for repairs. During normal operation when the pedal is depressed the switch closes and allows current to flow through the fuse to the stoplight bulbs. On newer vehicles lamps can be a mix of filament, LED or even neon bulbs.

Brake Light Bulbs

When the brake lights are not illuminating or some are and some are not, the most likely cause of the problem is a blown bulb. When discussing this specific topic the age of the vehicle becomes critical. The newer the automobile, the more likely it is to use advanced lighting technologies such as neon, LED, or even laser lit taillights that use fiber optic strands to deliver beams of light to lamp assemblies.

These types of lights achieve their maximum brightness within a few milliseconds, whereas conventional filament bulbs take about 200 ms to reach their full brightness. This provides an earlier warning for following drivers giving them more room to react to quickly changing traffic speeds. Not only is the new technology quicker it also last longer. Car manufacturers started mixing these exterior lighting technologies in the late 90s where it was common to have regular filament bulbs in the taillight assembly and the high mount stoplight LED.

Brake Light Problems

Some vehicles are prone to specific problems by faulty design. As an example, General Motors recalled W body cars in 1990, this included the Chevrolet Lumina, Monte Carlo and Pontiac Grand Prix’s. Failed brake switches caused symptoms on these models including lights that wouldn’t come on and cruise control that would fail to disengage when the brake pedal was pushed. Later on in the 90s, W body cars had problems again with the brake lights. This time malfunctioning combination switches in the steering column provided a unique set of circumstances where the high mount stoplight worked but no others.

General symptoms can still point to particular components. If the brake lights don’t come on at all the logical path of diagnosis would be to check the fuse and if that is okay then verify power is reaching the switch. Although it’s possible for this component to become out of adjustment, a miss adjusted switch is more likely to cause the lights stay on. Car manufacturers often make this part adjustable so it fits several different models and allows for a small amount of free play in the pedal.

When you boil it down brake light problems on older cars tend to be basic. Things like blown bulbs or bad switches are still the most common source of failures. As you progress through the years manufacturers began to blend in new technologies such as LED and neon bulbs because cool looking lights sells more automobiles. Regardless of the year of your vehicle, you should perform regular lighting maintenance checks to verify all the bulbs, light up when you step on the brake pedal.