Usually the "Hot Rod" kits have a switch with a light on it. By power board I assume you are referring to the "One Place Panel" there all the indicators, meters and thermostat are. If so that is done by Winnebago. If you use the switch on the panel, you need a relay to switch the power at the water heater.
2003 Winnebago Adventurer 38G F53/ V10 605 watts of Solar
1999 Winnebago Brave 35C F53V10 Handicap Equipped
1999 Jeep Cherokee, 1991 Jeep Wrangler Renegade and 2018 Chevrolet Equinox Diesel