Got a weird one for you, hope I can explain..
We had our 2001 Forest River Sierra 27FKSS plugged in at the house on a daily basis throught the week. One night when we got home we noticed all the marker lights were on.... Really confused since my understanding was the marker and tail lights only came on when the towing harness was plugged into the truck.
So I unplugged it, the lights were still on, so I unhooked the battery, then they went off. I am still unable to have the battery hooked up or plugged in without the marker and taillights being on. I can only assume its a short, but I don't even know where to start?? Do I have to disassemble have the trailer to find it???