For some reason, Thor chose not to color code the wires going to the house batteries. Typically, red is positive and black is negative. I replaced mine a couple of months ago and decided to turn them around so that the fill holes were closer to the front. I thought I had everything figured properly but still managed to screw it up and hooked them up backwards. The good news is that the distribution panel has a couple of reverse polarity fuses that protected everything. Once I got the polarity right, I replaced the fuses and all was good.
You have to take the internal panel cover off to access the reverse polarity fuses.
__________________
|