Battery issues

Check the two heavy gage wires that connect at the converter charger and go to the house battery to charge it. The connectors on the converter/charger have allen head set screws that need to be tight and bite into the two heavy gage wires. Also make sure that clamp connectors at the house battery are clean and tight, making good connection. Make sure that any small wires with ring terminals are connected to the correct clamp connectors. Check fuses in fuse block for any that are blown or making poor connections. A loose wire at a fuse holder caused the same symptom you have. Make sure that your disconnect switch for the house battery is in on position. You should hear a clunk from a relay when it is switched "on". Check voltage at house battery when rig is connected to shore power, should read 13.6 volts on your digital voltmeter set on 20 volt DC scale. With engine running, voltage at house battery should read around 14 volts DC. If converter charger is working properly, etc, it should take 24 hours to charge a near dead but good house battery. When you are driving, it may take a couple of hundred miles for engine alternator to charge the house battery and starting battery. The starting battery will not charge when rig is parked, engine off and plugged into camp/shore power unless a special device is installed Google "Trik-L-Start". Learn about battery charging system and keep batteries maintained and electrolyte levels above the plates using distilled water and a turkey baster filler from an auto supply store.