Gene M wrote:
I prefer to make what I have work.
"Gene M".....You're getting a lot of pushback on your idea, because it's a bad idea. Once you stated you're an engineer, it became clear that you're trying to engineer some complicated system to do what has been done for years without issues. You'll spend hours trying to wire up a system that will be flawed by too many gadgets trying to achieve what the propane does with a single hose. I suspect the complexity of what you want to do will cause you hours of grief as things fail, particularly the fact that you're only running one battery!
You're concerned about running down the road with propane on, yet your project probably has as good or better chance of catching fire electrically by this maze of wiring, under sized wiring and overworking an alternator and single battery. You already have one of the safest RV's on the road because it's built with a van front end. Don't let the non issue of propane paralyze you and keep you from RVing.
Take a moment and reread this entire thread. With every post you make, you're trying to overcome issues that are be presented to you. It doesn't make sense.
If you're trying to find fun projects to do your coach, pick some other improvements that aren't so complicated or valueless. Add a nicer water pump, improve the sewer hose setup, make the stereo system better, find hidden storage areas where you can make more room. This project makes no sense.