My lights on the outside of my fun lite hi-lo camper don't work. Could it be a ground issue?

Are you talking about the taillights and the marker lights? If so, first check to see if there is power coming from the tow vehicle, then work your way back. Do the turn signals work?

__________________
My Great Wife Joyce
2018 Jayco Jay Flight 21QB
Formerly owned 1705T and 2310H
2012 F150 4X4 SuperCrew EcoBoost w/Leer Cap
Reese WD Strait-Line Hitch
Amateur Radio K3EXU