First thing a Harley rider needs to learn is that, even though motorcycles are normally ridden outdoors where things like rain and snow and stuff happens, H-D has never seen a need to make anything actually waterproof. Therefore, you get water in your gauges, you get water in your switches, you get water in your stereo, you get water in your turn signals, you get water in bearings, and you get water in various and sundry electrical connections. The $1.95 gauges Harley has used for years make no pretense at being water resistant, much less water proof, so good luck getting your dealer to take this seriously.
This is where I would draw the line and refuse to accept the "normal" BS; if there is enough moisture to result in liquid being observed inside the gauge, not just fog or mist that dissipates, it isn't acceptable. That is the standard used in automobiles for exterior lights that have venting systems.
Jerry