Thanks Everybody for keeping us going!
I pulled the battery
and cut out the positive and negative wires connected to the red and white wires at the power converter. They looked fine but wanted to make sure and really didn't like the connection point anyway.
We ran through it all again today. We hooked up the battery
temporarily to the same locations at the power converter ... And no sparks!!
We're starting to wonder if we didn't have the plug into the tug tight and that caused the sparking?
We're still a little confused but everything (ac / dc / with tow vehicle only / with trailer battery
only) seems to be working. We're going to re-wire the battery to a Blue Sea fuse box under the gaucho and clean up the wiring under there. We're going to replace the seven pin wiring from the hitch plug to the gaucho. I may play with a negative wire to the trailer frame from the Blue Sea box.
And hopefully we'll be ready to camp soon!
Thanks again for all of the assistance.