Harry thats pretty odd
are you connected to shore power when you do this? If so can you remove or close breaker on shore power and try again?
I am leaning towards a misbehaving breaker..of course I'm a guessing
But at least you have work around for your trip
Let us know what you find out,
Greg and Vicki R.
2004 Country Coach Intrigue "Sweet Serenade"
40' Tag Axle Quad slide CCI #11811
16 Jeep Wrangler, Airforce One