I replaced my univolt with an Intelipower unit. As I was awitching the wires, I see a large blue wire that was labled on the connector board "to car battery circuit #5 agu 40" (or something close to that) BUT! before I re-connected that wire, nothing up front, the ammeter, water pump, water level
indicators, would work! I then hooked the big blue wire up, and all that stuff works!
It seems the center conductor was supposed to be the 12 volt
supply to the trailer, but it is not wired that way. That is part of the confusing part.
I have the original manual, and the plug diagrams don't even mirror eachother, which confuses me even more........it dosn't seem I am charging the trailer battery from the tow vehicle, either.
Originally, when I first bought this trailer, I had a "professional" hook up the brake control and running lights, which should have included the battery wire. It has been years since then, and all this time, I just thought the problem was the univolt, but now suspect that was only part of the problem.
Do the wires in the cord that plugs into the tow vehicle connect at diffent places than at the front? The brakes work OK, all the trailer lights too. Seems like one of them conundrums to me...