Mike:
We really need to know how old the motor-home is. What year is listed on your paperwork from purchase?
If it is brand new you have warranty and the dealer should find and correct the problem. It may be simply a missing ground or other connection.
What I worry about now is that the salesman dumped a used motor-home with existing problems on you. They spot a new customer to RVing who has the money, but no experience and take advantage of them.
I would get back to the dealer to find the problem. It might be you just need to be shown how to use the systems in the motor-home again. I hope that is the case.
