Welcome to the forum. The outlets are supplied power through shore power(coach plugged into the 30 amp outlet) or when the generator is operating. Unless the previous owner installed an inverter. Inverters can use your battery 12 volt power and operate limited outlets(usually the refrigerator or TV). Some owners install one outlet directly to the inverter to use for specific items(computer/light...) only. Like Lt. Keefer said Amazon has a wide selection of shower door seals to look at. You just need to match it up with what is currently on the shower door.
Paul
__________________
|