need help on a new build

I'm new to this eBike stuff. I've wanted to electrify my bike for some time, and a couple of weeks ago I bought a group of used parts. I got two 12v SLA batteries with covers and baskets, two brake lever/switchs, a twist throttle, a front wheel BLDC and a couple of controllers which were in need of some soldering. I was kind of surprised that none of the stuff has any identifying marks, so I cannot tell what make/model any if it is. I repaired the broken wires on one of the controller boards, charged up the batteries and plugged everything together. But it didn't work. There is one connector on the controller that I can't figure out - I don't know what it does or what it should be connected to. I've looked around in this forum and others and I have found only a very few wiring diagrams. I made a diagram of the stuff I have, let me see if I can post it here.

In my sketch there is a controller which connects to a small panel with a battery/power connector, a switch and an LED; there is also a potentiometer which I suppose is a maximum speed adjustment; a connector for the throttle/brake system; a connector to the wheel/motor with 3 power and 5 control wires. There is also a 3 wire connector with red, black and blue wires. I don't know what this connector is supposed to do. I imagine that this connector is the key to making my equipment work. If anyone can tell me what to do with this connector I'd appreciate it.

TIA

Dave H
Pleasanton,CA