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Headlights Keep Going Out? Check These Things

A halogen lamp bulb.

A burnt-out headlight means reduced visibility, which can put you and other drivers in danger. But what does it mean if one or more headlights keep going out? This is a problem that should be identified and corrected immediately. Here are some clues to help you troubleshoot the issue.

Failing Headlights: What’s the Problem?A classic car headlight.

Besides being a safety issue, a burnt-out headlight can also result in a traffic citation. While it’s considered a non-moving violation (which means no points are assessed), it can cost you plenty. This is especially true if the police officer notices other problems with your vehicle, such as a broken mirror or improperly installed aftermarket equipment, such as too much tinting.

Improperly Installed Bulb

If you replace a headlight and it burns out again quickly, there’s a chance the replacement bulb was not installed correctly or is the wrong size. If it’s not securely in the socket, the bulb may work loose and bang against the housing or fall out. In any case, the bulb must be secured in the socket to work effectively.

Bad Vibrations

Your headlight housing could also be loose. If the equipment holding the light bulb is not secure, the bulb could break, especially if it’s jostled. In addition, the wiring harness that connects the headlights to the voltmeter may be loose or frayed. If it is loose, disconnect the battery terminal’s cable and put the headlight housing back in order. Disconnecting the cable avoids a potential power surge. If the wiring harness is worn, it should be replaced.

Blown Fuse

A blown fuse can take out a headlight and indicate an electrical problem. A fuse blowing could be caused by one of two issues:

1. Improper Fuse Replacement. Replacing a fuse with a higher amperage will cause a blow out. To rectify this problem, visit your owner’s manual and look for the fuse schematic. Typically, the fuses are color-coded and sized differently. Theoretically, a different size shouldn’t fit, but you’ll want to be sure to install the right kind of replacement fuse anyway.

2. Short Circuit. A blown fuse can sometimes be attributed to a short circuit. Specifically, fraying of wire insulation, a faulty voltmeter or a bad conductor somewhere in the car can cause this. You may need to perform a more comprehensive review of all electrical connections, starting with your battery and alternator, before you move forward.

Condensation or a Leak

Water is the enemy of electricity, and it can quickly extinguish a bulb. Although moisture isn’t always detectable, condensation on the headlight housing cover is a clue. In more serious cases, the housing is exposed to the elements at the seal and collects water. If you hit a bump while driving with the housing exposed, a splash could douse the light. Sealing or replacing the headlight housing should resolve the problem.

Temperature Extremes

Although it’s not a likely cause on its own, extreme temperature can cause bulb filaments to fail. Particularly during intense cold, lighting filaments can become brittle and break. Bumpy roads can exacerbate this problem and lead to more frequent bulb failures. If possible, park your vehicle in a garage during cold snaps.

Light It Up

In addition to your headlights, you should also check all exterior and interior lighting regularly. Bear in mind that some bulbs burn out without notice or warning, so you’ll want to make sure they have the best operating conditions possible.

Check out all the headlight products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on why headlights keep going out, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo Courtesy of Pixabay.

Matthew C. Keegan View All

Matt Keegan has maintained his love for cars ever since his father taught him kicking tires can be one way to uncover a problem with a vehicle’s suspension system. He since moved on to learn a few things about coefficient of drag, G-forces, toe-heel shifting, and how to work the crazy infotainment system in some random weekly driver. Matt is a member of the Washington Automotive Press Association and is a contributor to various print and online media sources.

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