I have a 2016 13 ft Scamp.  This past weekend when I plugged in my camper to the car, the lights on camper did not work.  I went to Hitch n Go today, they did a diagnostic test and said the plug in on my car was working fine.  Where do I go from here?  I have had trouble also with the power not working on 12v when my battery is fully charged.  I ended up changing the 20amp fuse on the battery wires and then the lights worked.  But now, once again they are not working on battery power.  Any help would be appreciated.

Kay B