Thank you for the advice everyone.
The problem turned out to be a very silly one. The bolt on the Super Multiple Junction was not tightened, and so it was not plugged in all the way.
Unfortunately I only found it out after already ripping open the harness and removing every unnecessary wire. Although having less wires is nice.
And since I already have my harnesses exposed, now I am in the process of trying to make the headlights go up and down again.
