Symptoms
- Visible crack or chip in the headlight lens
- Water pooling inside the housing after rain
- Bulb burning out repeatedly in that headlight
- Fogging that never fully clears
Likely causes
- CommonImpact damage from a rock, debris, or minor collisionRoad debris or a minor bump can crack the plastic lens, creating a direct path for water.
- PossibleStress cracking from age and temperature cyclingPlastic lenses can develop small stress cracks over many years of heat and cold cycles.
What to do
- Inspect the crack size and location to determine if a temporary seal or full replacement is needed.
- For small cracks, clean and dry the area thoroughly before applying a clear, UV-resistant sealant as a temporary fix.
- Check inside the housing for any standing water and dry it out completely before sealing.
- Monitor the bulb and connector for corrosion if water has already gotten in.
- Avoid driving through car washes or heavy rain until the crack is at least temporarily sealed.
- Plan for full lens or housing replacement, since a sealant is only a temporary measure for a cracked lens.
- Check that the headlight still aims correctly after any repair or replacement.
- Have a shop replace the housing if the crack is large, in a hard to seal spot, or has already caused water damage inside.
Tools and parts
- Clear UV-resistant sealant (temporary fix)
- Cleaning cloth
- Isopropyl alcohol (for cleaning before sealing)
Replacement headlight housing/assemblySearch: “headlight assembly for [your car make model year]”
When to call a pro
A cracked lens should be treated as a temporary situation; plan to replace the housing soon to prevent ongoing water damage.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.