Winnebago Won't Start in Morning & Damp Outside

My instincts wonder if maybe you have a coil that is going bad. I know people have mentioned issues with after market wires, but I have yet to ever have a problem and have always bought after market. Next time you have an issue, unbolt the coil from the engine and lay it on a piece of cardboard and try and start it. When coils go bad, most of the time they short to the core. If the core is isolated, it will prevent it from shorting and it will run.