I have a 2005 Fleetwood Sea Pine. It’s been closed for the last 4-5 months, but we had a sunny day yesterday so decided to open it up. Right away noticed the voltage meter was at 0 so I grabbed the multimeter to test the battery and it read 12.1V. The outdoor light and the water pump both worked, but both indoor lights, the heater, and the voltage meter would not work. Checked the fuses inside visually and with multimeter and all were good. Plugged the camper in to AC power and everything remained the same. I’m stumped and don’t know what to do next. Any suggestions would be appreciated. Thanks!