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Q: Keep needing new headlight bulbs, why is this happening?

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Not sure why, but my higher-mileage (105k miles) 2006 Kia Sorento is burning through headlights just one after another. A headlight lasts 6-10 weeks on average. This is starting to get expensive, and now my brake lights are burning out too! What is the issue here? The wiring? The battery? I have no idea where to start.

A: Hello, replacing bulbs frequently can be bo...

Hello, replacing bulbs frequently can be bothersome.

A couple of reasons come to mind. If you are using the cheapest bulbs possible, the cheap filaments may just be failing. Trying a good quality bulb may be a good start.

You may also be having a problem with your alternator. If the alternator is over charging, it can cause undue stress and overheating of the filaments. An intermittent fault with the alternator could be harder to find. Unfortunately, the charging system warning light is not the best indicator of a problematic charging system voltage.

To properly check the charging system for failure requires connecting a volt meter and then driving the vehicle to see if the voltage goes higher than the recommended max voltage. It is possible that when the voltage spikes and the bulbs are illuminated, the filament is being overloaded.

A certified mechanic, such as one from YourMechanic, can evaluate your headlights and brake lights to find the underlying problem.

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