[KenWittlief]

the black box you are talking about is just to connect a bunch of wires together - you already got the basic idea, the heavy #6 wire from the 120 Amp circuit breaker goes in one end, and you can attach four #10 wires to the other end, one for each of the 40 amp breakers in the clear plastic fuse box

the middle set you dont need to use, and the bottom 'buss' lets you connect the black #6 wire from the ground stud, or the negative side of the battery, to the - terminals on the 4 victors that you are using for your drill or chips motors

btw, if you are only using 2 drive motors, you dont need to put wires in for all four 40A breakers.

check the wiring diagram in the manual - it should make more sense now.