I'm hoping someone can help me figure out the purpose of a green switch located in the entryway of my Rockwood 1904. The User Manual is of no help with this one. The switch is located directly below the CD player/radio unit. It lights up when switched on. It is NOT the water pump switch; nor is it the switch to control the overhead lights. The camper is new to us, and we have only done driveway camping so far...so I am thinking that the purpose of this switch may become clearer as we try to operate the other systems in the camper (such as water heater, furnace, etc.). Any words of wisdom will be greatly appreciated!!!