Thanks for quick reply!
I think i'll just get a new controller from ebay, since the power probably comes to the monitor from the controller. Both wires i got can't be both bad xD. The only thing left would be the motor itself and it wouldn't make sense that the main harness could short it out.
So my kit is bbs02b with hailong downtube battery, dpc18 monitor.
Recently i got an "error code 30 communications error" and then i disconnected the harness wire (green) and reconnected it. It no longer turned on. I went back home and i checked the harness and one pin was twisted (on my...