I'd check the cab lights,as well.on my windshield channel,i had a few areas where the rubber was dried-out,and getting bad. I gently pried these areas up,(between the channel and metal,IF metal's not rusted),and carefully laid in a thin bead of neoprene. (Caulk gun type). The reason i chose neoprene,is because it stays pliable,in almost any kind of weather,and lasts about 30 years.I had a couple of marker lights,that didn't seal between the gasket,and the roof. water was getting in through the wire grommet. I pulled the housing up far enough to run a bead,making sure to seal the grommet,as well. for clean-up,just soak a corner of a lint-free rag in gasoline,and it'll clean-up,without damaging the paint,or trim,(if equipped). Hope this helps.
