Welcome to irv2.
03 coach seams sealant has started to dry up and seams need to be looked at on roof, radius wrap to sidewall and window top seams for cracks to allow water behind the outside wall surface.
Here are
some good materials to do just that.
I have been resealing my 03 coach on horizontal outside floor seams, over compartments, windows, roof area wrap to side wall, vertical seams to front and rear caps and plan to tape all roof seams with the E-Bond tape.