The power to the trailer works fine while plugged it. No power from the charged batteries to the trailer. Cells filled with water. Connections tight. No fuses appear to be blown on the converter. The last time I used 12 volt power was to extend the slide room. That worked. The next day, no 12 volt power while traveling. Is there a relay to reset? It seems to be something like a fuse or relay but I can't find one to reset / replace. Any ideas? Has this happened to anyone else?