Well, yeah, that's sort of the weakness with ALL idiot lights, if the lite bulb itself that lights up the idiot light fails then the whole system is not gonna tell you there is trouble:Tomfoolery wrote:A float switch configured like that is not fail-safe: if the circuit or bulb or LED fails, it indicates "full" when it may not be. As to the level sensor, while it's true you don't need to see what's going on in the middle, I suspect you'll see the float moving a bit when full (on the gauge) which is an indication that it's working correctly, as there's constant feedback. You could even mount it to another cup, similar to the one the vent is in, so it will definitely not show a pegged needle when full, at least until the boat is heeled, at which point it will be fully submerged.
And that also goes for the idiot lights that are already on the helm that tell you the engine heat is too high, or there is no oil pressure, or that the battery is dead (one of my favorites because a dead battery can't light up a light!! (how stupid is that!)
And don't forget the infamous "Engine Light" that everyone has on their cars now! (More stupidity).
Yes, of course I would always prefer gauges over idiot lights for the same reasons that I do not like idiot lights on my car, but let's face it - idiot lights are what we get, and they are better than nothing.
To your point, if there is a good way to mount a decent sender in there that can handle the salt water I would be willing to go that route but not if it's going to cost a bundle and put holes in my ballast tank.
I'm totally open to a gauge and would prefer it over an idiot light all day long, but is it possible without tearing up the boat?