Converter putting out 16.5V, some appliances don't work.

I owned a popular Progressive Dynamics 9245 which went bonkers and started putting out too much juice - fried all the expensive electronic components in the RV and boiled/ruined the batteries too boot. PD replaced the converter which was a tiny fraction of the damage done. If I had a converter which put out too much juice I would disconnect from the electrical system, contact the mfg, and look around for possible replacement.