Have you accounted for every black wire that lands on the breakers?I am hoping these were from the auto bar, but I need to trace the neutral to find the hot and ground. But no it's not easy at all to get to where the auto bar wires are. There exactly where the bar is and where the wires disappear behind it. Coming in from the other side behind the steps is where all of the wires come in to the panel, but there is about two feet of the bar that stops it from being accessible. Not to mention it is all bundled and wrapped in wire harness covering and wire tied.
There had to have been a black wire that accompanied the white one.