Say have not had a chance to look into it to deeply and have not owned this Airstream very long. 1977 Overlander has no lights working when running on battery. The power is there because the water pump works and the light works on the overhead console. Probably not the right name, I am talking about the device that measures your tank levels and so forth. Any easy thing I might look into to get the lights to work with battery. Works fine when pluged in. Thanks for all the info the forum is great.