on my 2019 Southwind 35K it is behind the passenger rear wheels! Apparently they move em all over! The red reservoir under the hood on my coach is engine coolant.
That switch is used for the ceiling lights, when the bed above the captains chairs is in the down position. So the person sleeping up there does not have to get down to shut off the lights.
Thanks for all the advice! I am leaning to having it repainted from black to gray. Perhaps the gray won't fade as the black did.... I will see if I can get some prices from some marine guys....