This morning I went out to clean the trailer and I have no power. We have a Progressive Industries surge protector/power monitor in it and it shows no error code and voltage coming in to it is good. ...
Are you saying one GFI powers the whole trailer? The way you posted your problem is that is what is going on plus a dead battery as none of the 12v lights work either. My question is, does anything work in your trailer? More info would be helpful.