If the converter is working (by the way, Do you know it's make and model) but the batteries are not charging either on shore/generator power OR engine power.. My first suspects are the AUX disconnect switch and solenoid, Suspect #2 is any circuit breaker that may (or may not) exist between battery and said solenoid.
IF you have an Intelletec Battery Control system under the hood.. Look at the bottom of it and see if there are a pair of PUSH TO RESET circuit breakers there .. If so push up VERY HARD. Other makes of battery control systems, Likely have a similar feature but I do not have the manual.
Next suspect is the battery cable ends, all 4 (or six or however many) of them, Are the connections good and clean?
Home is where I park it!