All vehicles are required by law to have operating tail and brake lights. Your tail lights may be the same bulb as your brake lights (a dual filament setup) or they could use a separate bulb. In any case, you need working lights or you risk not only a ticket, but creating an unsafe driving situation for yourself and others.
Tail lamps are use in conjunction with your headlights, as well as your daytime running lights. They provide additional visibility in the rear, allowing drivers behind you to see your car in low-light situations (fog, rain), in the dark, and in the glare of direct sunlight (when used with daytime running lights).
Your tail lamp bulbs see more use than almost any other bulb on your car, with the exception of the headlights. They’re on any time you turn on your headlights, of if your daytime running lights are on. That’s a lot of use. However, the real determining factor is the type of bulb used. Some bulbs can last for up to five or six years (traditional, incandescent bulbs). However, LED bulbs have a life expectancy of 12 years or more.
Another factor that can affect the life of the vehicle is the amount of voltage being sent through the wiring. The higher the voltage, the shorter the lifespan of the bulb. You’ll also find that the areas in which you drive can reduce the lifespan of your tail lamp bulbs. For instance, if you drive over bumpy roads, down dirt roads, or in off-road situations often, the increased vibrations can break the filament in your tail lamp bulbs (note that this doesn’t affect LEDs the same way).
If your tail lamp bulb fails, you run the risk of getting a ticket, or even worse, being involved in an accident because a driver behind you could not see your car in time to stop. There are very few symptoms to watch for that indicate you need to replace the bulb:
- Tail lamp not working (one bulb out is generally a bulb failure, but if both are out, it may be the fuse)
- Tail lamp working intermittently (this indicates a wiring problem, not a bad bulb)
If your tail lamp bulbs are out, a certified mechanic can help to inspect or replace the bulbs, the fuse, the wiring and have you back on the road safely in no time at all.
This article originally appeared on YourMechanic.com as How Long Does a Tail Lamp Bulb Last? and was authored by Valerie Johnston.