A solid electrical system troubleshooting document

I know on my MH The converter will supply DC Power even if the batteries are disconnected. So on mine, I would check to see if the AC to Converter is turned on. This would give me DC power while plugged in. Next I would check out the DC disconnect controls, switch and solenoid. IMHO, you would have to have a major problem to blow the main battery fuse. Do you have light, water pump, refrigerator(RV unit not house type) in the RV? They run on DC. This should get you started to find your problem.