If yours is wired similar to fifth wheels it may be that a wire separated. The wire runs inside the tube that travels back and forth and are not always spliced very well. You can only find it by dropping the pan and gently pulling on the wire. Mine was a heavy lamp cord type wire that had separated from its splice due to friction when the slide moved.
Terry and Carol
Daytona Beach, FL
2013 F150 XLT, SuperCab, Ecoboost
2010 Rockwood 8285WS
2014 - 57; 2015 - 91; 2016 - 171