When installing the new house battery, did you forget to connect one of the small wires with ring terminal. Look around in the house battery compartment for a reset button. Is there an "auxiliary battery" or 'storage switch" in a control panel, try pressing it so red LED comes on and you hear a relay go "clunk'. It is possible that switch is bad or relay is stuck, push switch repeatedly and see if interior lights come on. Check the two heavy gage wires that go from the converter charger to the battery. There are allen head set screws that bite into the stripped end of wires that may have become loose in a connector block on the front of your converter/charger. Wiggle the wires that connect to the fuse holders in the fuse block, look for a loose screw connection. Consult an RV repair service that has an RV electrical expert. Fairly common problem!!
