I think you have more than one issue, I mean separate issues, not related to each other.
Carbon Monoxide detectors have roughly a 10 year life span, smoke detectors also have a limited life span. They do wear out, they go bad, they are meant to be replaced. Take yours off and look at it, it may have an original date or an expiration date. While you have it off, throw it away and install a new one.
I'll stay out of the electrical and propane issues, others are probably more able to advise you on that. My advice would be for you to call a good reputation mobil rv tech to come out and diagnose your electrical and propane problem.
Good luck to you.
