Have you looked to see if there is a junction box attached to the frame under the slide?
They have been known to not be sealed and get wet. Also the wires in the box are usually joined with wire nuts, which come loose. If you find that to be the case, when you re tighten the wire nuts, tape them together good with electrical tape.
Have you pulled the wall plates on the plugins to see if the wires have come loose there?
Just a couple things to check.
2008 Cruiser CF26RK
135 Watt Solar Panel
2013 Ford Eco-Boost
Heavy duty payload - Max tow