Headlight bulb keeps burning out repeatedly

Symptoms

• New bulb burns out again within weeks or months
• Bulb looks discolored or has soot inside the glass when removed
• Headlight housing shows signs of moisture
• Issue is limited to one specific headlight

Likely causes

• CommonMoisture inside the headlight housingWater intrusion can cause premature bulb failure from thermal shock or corrosion.
• CommonTouching the bulb glass with bare fingers during installationSkin oils can create hot spots on the glass that cause early failure.
• PossibleExcessive vibration from a loose housing or bulb socketVibration can stress the filament and shorten bulb life significantly.
• PossibleCharging system overcharging the electrical systemExcess voltage from a faulty alternator can burn out bulbs prematurely across the car.

What to do

1. Check the headlight housing for any signs of moisture or fogging that could be affecting the bulb.
2. When installing a new bulb, always handle it with gloves or a clean cloth, never bare fingers.
3. Check that the bulb socket and housing are securely mounted with no excessive looseness.
4. Have the charging system tested for overcharging, since consistently high voltage can burn out bulbs across multiple locations.
5. Inspect the connector for corrosion, which can create resistance and heat that shortens bulb life.
6. Try a different, reputable bulb brand if a specific one seems to be failing unusually fast.
7. Note if other bulbs around the car are also failing more often than expected, pointing to a voltage issue.
8. Have a shop test the housing seal and the electrical system if the bulb keeps failing despite proper installation.

Tools and parts

• Gloves for bulb handling
• Multimeter (optional)

When to call a pro

If bulbs across the car (not just headlights) seem to be failing prematurely, have the charging system checked for overcharging as a root cause.

Safety