How to Diagnose & Fix a Water Leak in Car Trunk

Most of the time, when you find water in the trunk of your car — it is coming from the tail lights.

The trunk of most cars is designed to send water that falls on the back window thru channels on either side of the trunk and out the back of the car. Oftentimes, as a car ages, this water gets into the taillight assembly, and then goes through the light fixture into the trunk.

Ways to Diagnose

1. Close the trunk
2. Run hose water against the back window to simulate rain — and run it for a good 5 minutes.
3. Open the trunk and examine all walls for leaks — but especially examine the areas by the right and left tail lights.

In most cases, all you need to do is add Sealant to the places where the lights go into the trunk.

This video shows you how to do this. It is for a 2017 Ford Taurus Police Interceptor — but really can apply to any car.