My holding tank heater switch is not lighting up when I turn it on. Is this an AC circuit? There doesn't seem to be a ckt breaker for it. Does anybody know how to test the switch? It has three wires going to it which is confusing because if it is a DC circuit it would have two. There is a Black, Red, and White. White must be ground because it is going to brass. Winter is coming and I need to figure out if the switch need replacing or something else.
Forest River Sierra 323FK
Solomon's Rec Center