I have a 1978 Itasca Winnebago, 24 foot length. Found out today that the inside lights do not work, 12 volt powered lights in the back. They used to work. Have done nothing with it this summer.Lights used to work. Checked the fuse box under dash by steering wheel. Fuses there are good.Headlights,wiper,horn, dash radio work. Battery good, wires to battery good. Generator in rear does not start. Separate problem.Water pump in back also does not work, used to work. Any help appreciated. No reference book to go to.