Headlights aren’t just convenience accessories – they’re required for driving at night. They’re also important for safety, which is why so many modern cars come with daytime running lights as a standard feature. Of course, light bulbs have a finite lifespan, and this should be listed on the package of the bulb you purchase as you’ll eventually need to change them. If you’re finding that you have to replace your headlight bulbs very frequently, it’s a sign that there’s something wrong.
Possible reasons for frequent bulb burnout
There are several potential issues that might be resulting in shorter than usual light bulb lifespans on your car. However, bear in mind that the more frequently your lights are used, the faster they’ll burn out. If your car has auto daytime running lights (that is, more than just the parking lights), or you do a great deal of nighttime driving, you’ll definitely go through bulbs faster than other drivers. There are other possible issues:
Skin Contact: If you replace your own headlight bulbs and you touch the bulb’s surface with your bare skin, you’re shortening the lifespan automatically. Contact leaves oil from your skin on the bulb, which creates hotspots and shortens the bulb’s life. Wear latex gloves when changing your lights.
Bouncing: If the mounting location of your bulbs isn’t secure, there’s a chance that they could bounce. Excessive vibration can break the filament (the part that heats up, creating light) inside the bulb. If there’s play in the bulb after installing it in the housing, you may need a new lens.
Incorrect Installation: Light bulbs need to be installed smoothly, and without any jerking, prying, or other stress. It’s possible that an incorrect installation procedure is damaging the bulb.
Incorrect Voltage: Headlights are designed to operate with a specific voltage. If your alternator is beginning to fail, it’s possible that it’s creating voltage fluctuations. This can lead to early bulb burnout (and you’ll need to replace your alternator, as well).
Condensation: The interior of your headlight lens should be clean and dry. If there’s moisture inside, then this will collect on the surface of the light bulb, eventually making it blow.
These are just a few of the problems that could be causing your bulbs to fail early. The best advice would be to have the problem diagnosed and repaired by a professional mechanic.
This article originally appeared on YourMechanic.com as How Frequently Do Headlight Bulbs Burn Out? and was authored by Valerie Johnston.