re: Pulled the wiring harness from my fifth wheel

The incoming 12v- wire is white which I have connected to the wire going to negative connection to the battery. There are 3 or 4 more white wires on the trailer side of the junction box. I currently have these hooked up to the 12v-. With all the lights working I’m left with the two wires from the break away switch, the blue wire from the truck wiring harness, a blue wire from the trailer, a blue/white wire that feeds directly from the rv battery, the aforementioned 3 or 4 white wires.

If the white wires aren’t negative where do they go? Serious question cause I’ve tried all I know.