As many have repeated the same experience before us, we arrived at our destination campground on the first day of our road trip, parked, connected to shore power, and the DC 12V power supply was dead on arrival. Our 12V converter probably died while our Casita was parked in its home berth connected to shore power between road trips, and I didn’t notice it. Fortunately, our solar panels kept the battery charged to serve the onboard 12V system for that road trip. It’s always good to have a secondary backup.
How did I know our converter was dead?