j-d wrote:
Watch out for weak and failed GROUND connections. Your batteries (chassis and house) should be securely grounded to the coach chassis. Your house wiring should be grounded back to the chassis too. If ground isn't solid, a light you turn on can try to "find" a ground through another light. That light may in turn light, or glow.
That is what immediately popped into my head.....one or more corroded ground connections. Corroded chassis ground connections is a very common problem in older rigs....even newer rigs that are driven in winter where salt spray messes them up.
Clean up each ground connection you find, typically an eyelet on the end of a green or black wire, held against a piece of metal frame with a sheet metal screw. Replace the screw, maybe even cut a new clean end and add a new eyelet. Once it's all back together, Smear a good amount is silicone grease to slow down future corrosion.