Agree with those posting it most likely the converter. Experience the same symptoms several years ago with lights dimming on our 08 Bounder. Had to replace the converter, which was a straight forward job. My converter was located behind a rear bedroom drawer.
Posted this on a previous post a couple of years ago:
If you do need to replace the converter I highly recommend best converter
http://www.bestconverter.com/ They were recommended from many others on this forum. I was very happy with my dealing and purchase from them. I purchased the Power Max Boondocker 75 amp