Panel seems to kill circuit

I am using a Renogy 100 watt panel in an A-liner camper With a Wanderer control unit. The panel is charging the battery according to the control unit but the DC does not work in the camper (even though the control unit shows a charged battery.) The DC then works when I plug into the 7way trailer hitch. Makes no sense to me.
Comments
1) Always double check the +/- wires on the panels... Sometimes there are wired "backwards" (custom panels, mistakes, no connectors). If you put a panel "backwards", the "diodes" of the solar cells will be a short circuit. If connected directly to the battery bank (or a large array) backwards, it will blow fuses/breakers (if present) and probably smoke the panel.
2) When working with solar charge controllers... Always make battery to controller connections first, then connect (or disconnect) the solar array. If you connect the array first (in sunlight), it is possible to confuse the controller (boots incorrectly) and sometimes even fry the controller. If you have been playing with the charge controller, a) first disconnect the array and b) disconnect controller from battery bank--And reconnect (controller to battery bank first) after a few minutes of no-power.
-Bill
I don't think you reversed the panel connections. But you may have an open somewhere between the battery bank and the main DC panel (it sounds like).
Good luck,
-Bill