Also check the fuse or breaker on the converter. Put a meter on the output of the converter while it is plugged in. Bet it reads the same as the batteries, which means no output of the converter. If it needs replacing, be sure to get the newer style "smart" charge technology - - only costs a few dollars more and it will save your batteries.
2003 Dodge HO 6 speed Laramie Dually, Jordan controller, RDS fuel tank, Air Ride 25K hitch
Carriage 36' fiver, Onan 6500, Prosine 2K inverter, 3 slides, MORyde IS and Kingpin