The converter works the lights but not the furnace or battery charging. The battery with no converter runs the lights and the furnace.
Is this one of those 6300 converters with a split DC fuse panel and a separate charger section?
If so, you can have a stuck relay that gets the battery charger working, while the rest of the things (lights fans) that don't need battery as filter work or as well have only the battery direct side of the panel working with no battery as a filter to run the furnace and other sensitive items (range hood monitor, fridge, WH 12v side.) Or I am all mixed up, not for the first time! :(
