Symptoms
- Visible water when removing the taillight housing
- Bulb corrosion or failure inside the affected taillight
- Wet trunk carpet near the taillight mounting area
- Fogging visible inside the lens after rain
Likely causes
- CommonFailed gasket where the taillight mounts to the bodyThe rubber gasket seals the gap between the housing and body panel and can degrade over time.
- PossibleCracked lens allowing water entryImpact damage can crack the lens and let water in directly.
- PossibleClogged trunk or body drain redirecting water toward the taillight areaWater that should drain elsewhere can pool near the taillight mounting instead.
What to do
- Remove the taillight housing according to your vehicle's specific method to inspect for standing water.
- Check the gasket around the mounting area for visible gaps, cracks, or a poor seal.
- Inspect the lens itself for any cracks that could be a separate water entry point.
- Dry out the housing and any affected wiring or bulb sockets thoroughly before reinstalling.
- Check nearby trunk or body drains for clogs that could be misdirecting water.
- Replace the gasket if it's visibly degraded, using a new one matched to your vehicle.
- Reinstall the housing carefully to ensure a proper, even seal all around.
- Have a shop perform a water test after repair to confirm the leak is fully resolved.
Tools and parts
- Screwdriver or trim tool
- Clean cloths
Taillight gasket/sealSearch: “taillight housing gasket for [your car make model year]”
When to call a pro
If wet trunk carpet accompanies the taillight leak, have a shop check for a more extensive body seal issue beyond just the taillight itself.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.