2004 four winds 28' class c, checking for first outing of the year, no 12 volt power, test light lights at cables & junction near coach battery, does not light at cables going into convertor
Make sure you haven't accidentally triggered the battery shut off - location can vary. In my rig it's a toggle switch by the drivers left knee. Also - there maybe an auto reset circuit breaker (usually located near battery) - if that goes toes up then no juice gets to/from the battery. It doesn't look like typical circuit breaker so use google.