Here's the latest. Thor customer service claims they are not aware of the problem. I inspected the upper grill and found two of the mounting screws loose. On one of them, the grill lattice had sperated and the screw was holding air. Someone had also put rubberized caulk around the perimeter of the grill. Thor CS stated this rubber was not factory installed. Since one of the grill hold down tabs is destroyed, I am pricing a new grill from the local Thor dealer. However, I am going to remove the grill and run in the rain to make sure it's the problem. I'll keep you posted. Thanks Kenneth, I think you put me on the right track....
__________________
|