There should be two 30 amp fuses (green) in the converter. One is the main fuse to connect the converter to the 12V system. The other is a reverse polarity protection fuse to protect the converter if the battery is connected backward. Likely one or both of theses fuses are blown. If this is the case your battery is not being charged either.
If that is not it you may well have a bad converter.
The switch that 19h f250 is referring to will not be the problem. If it were the lights would not work on battery either.
Chuck - Sparta, TN
2012 Jay Flight 22FB, 2 x Honda EU2000i
2013 GMC Yukon XL Denali AWD
EDUCATION is what you get when you read the fine print.....
EXPERIENCE is what you get when you don't.