AtlantaRick....Your symptoms sound like a ground issue. When you first start your coach, especially if it's cold out, your fuel rail heater comes on and draws a LOT of power. It will usually make your voltage gauge jump all over for a minute or two as the heater turns on and off. This with your previous symptoms sounds like your sending unit isn't getting a good ground.
Your coach has a Centroid http://www.centroidproducts.com/moncal.htm
sending unit. It's located on top of the tank on the driver's side. The top of the sending unit is about 3" in diameter and has adjustment screws and wires held on by nuts. I would open the bay door (remove screws from under the panel and lift the panel up) and clean the connections. As with most Monaco products, they sprayed undercoating on everything, including the sending unit. Loosen all the nuts, make sure everything is clean and retighten.
If you get everything working, you can also adjust the needle on your fuel gauge to where you want it. There are adjustment screws on the top of the sending unit.
I adjusted my unit when it was new to make the needle on thegauge go to where I wanted it. About four years later, the gauge started doing crazy things, some similar to yours. I called Centroid and they said I should check for algae issues on the interior portion of the sending unit. I knew I didn't have algae issues and decided to adjust the needle one more time before I replaced the sending unit. It has been fine ever since.