Half my Electrical is Down - Help

While camping this weekend at the Oregon Coast, I lost power to an entire circuit on my 1977 Argosy 22.



While plugged into 120v, we came back after a day at the beach to find our water pump, various lights on the port side of the trailer and our Fantastic fan were not working, completely dead like a blown fuse. All other appliances and lights work.



I diagnosed by checking all fuses, flipping all breakers even though none were tripped and nothing came back on. I then disconnected the 120v plug to go back to 12v and nothing came on. I then checked the fuses up front for the trailer lights and inspected the fuse on the water pump and fantastic and everything checked out. I am at a loss of what to do next or if there is something I missed.



Also of concern was while plugged in we were at 13 volts on my meter and after unplugging I dropped to 10.7v in a quick time. I believe my batteries are in good order as they are new and I kept them well maintained over the winter. No issues before this weekend. Does this maybe indicate a short? Would a short drain batteries?



Please help. :blink:

Thanks,

Jim