Everytime it rains a decent amount, the back seat of my 1997 F-150 3 Door cab gets soaked. I patched up the weather stripping parts that run from the front windshield to the rear shield. I also took out the back taillight that runs up over the back window and patched around it. The water runs through the top of the headliner. Anybody have any idea where it could be coming in?? Thanks

 

the back window maybe? id check the 3rd brake light again, both the seal against the truck, and the seal around where the wires go into the truck. Possibly front window up top too.
-Patrick

 

If not through the weather stripping of the glass or brakelight, maybe the whole rear window assembly is letting water in. When you go to your truck and feel the top of the trim around the window you will easilly be able to tell water can very easilly get threw that crack and fall in.