Rear Passenger Side Floorboard Wet

[chevy5150]

The floorboard behind the front passenger seat is wet. Can anybody help me figure out where it might be coming from? It's not wet anywhere else but there.

Thanks,

Bryan

 

[PlazaEJ]

I recently diagnosed a 2012 Lucerne, with the same problem. Turned out that the vapor barrier on the inside surface of the door ( behind the door panel), had come loose, and was allowing rain water to run down the inside surface of the door. You might look for excessive warping of the belt molding, also. It could be letting more water than usual inside the door.

Good luck,
EJ

 

[YukonXL04]

The floorboard or rocker panel on that side could be rotted out...