Do yourself a favor and get this moisture meter, this thing works!
Moisture meterGo along the walls, cabinets and floors with this baby and it pinpoints where all the moisture is centered. This unit can detect moisture between 1/2 to 3/4" below the surface. Don't slide it across the surface lift it as you move it.
I went through my house with this baby and found one spot beneath a sliding door that was leaking a bit and soaked into the floor, and another spot on the wall of my store room pointing to a leak in an outside plumbing pass through.
Good luck with your camper.
Ron W.