I had similar problems last winter in Florida, called RVP and it took the tech about 30 seconds to tell me that I needed a new board.
Lazy Days in Tampa had 2 in stock at a price very close to the internet plus shipping. I picked it up and installed it the same day. As mentioned before, read and study the directions carefully before starting, otherwise it's not a difficult project.
Denny, Connie & Shadow (former barn cat made good)
2000 Itasca Horizon, Cat 3126B, Freightliner Chassis