That s your 3rd brake light.
Ram 1500 third brake light leak.
The gasket on the 3rd brake light is a foam sponge that deforms easily and leaks.
If they used the same kind of gasket on the new brake light once it saturates it leaks.
Fixes 3rd brake light leaks.
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Dmt 2009 2018 dodge ram and 2019 ram classic third brake light center high mounted stop light chmsl gasket.
2009 to 2018 dodge ram 1500 2010 to 2018 dodge ram 2500 3500 this product features as a replacement and upgrade for the old third brake light seal gasket made of thicker and firmer foam prevent water from leaking in effectivly also more durable than the old one ideal solutionn for the annoying water leak problem.
Best solution is to take that gasket off and replace it with the weatherstrip from lowe s or something similar.
This gasket is a 187 thick automotive spec epdm foam rubber gasket.