Hi guys,
I have a 2007 Lariat that has water accumulate after rains in the drivers side wiring channel along the running boards and doors. I have changed the 3rd brake light and now siliconed it in place, checked the drain tubes of the the sunroof, removed head liner and interior panels to gain access to front window... and rear and still do not see any evidence of water. The only thing I can see left is the upper side of in cab fender where i cannot see..... a body drain or seam may back up and weep in????? anyone have any ideas

 

Look at your A-pillar between the door hinges. I had the weather tube around my wiring harnesses pop out once letting water come in there. May also look around the windshield area.

 

I second the windshield.