10-30-2021, 07:45 PM
The 12 volt lighting is powered off the batteries. The 120 volt power will NOT power the 12 volt systems directly. The 120 volt system runs a battery charger that slowly recharges the batteries. The reason the 12 volt systems started working when you started the coach was the engine alternator started providing 12 volt (actually around 14 volts) to the batteries AND to the coach's 12 volt system. As your batteries get close to 12 volts, the built in battery charger will provide enough voltage and current to turn on the 12 volt lights but at less than 2 volts, the batteries are acting as a block to the prevent the lights from coming on.