KT controller question


Esteemed Pedelecer
Jan 26, 2015
The European Union
I have a three or four year old KT controller - 36v 15 A

All of the wires bar one I can identify. The rogue wire has a male plug and is yellow and black, the yellow wire is connected to a small PCB soldered to the main one. It (the small PCB) has a diode and another black cylinder soldered to it.

I can't remember it being plugged into anything, the brake switches are also yellow and black and have female sockets, there is a red, white and black throttle wire (speed sensor is internal so handled by the motor wire) and yellow green and red PAS.

Any ideas?