Solved: Hub motor wire shorted, replaced cable, but still not working

Hi,

I have a generic 1000W hub motor with a 1500W KT controller (~3000W modded) and KT LCD3 display with a simple FT-21X finger throttle.

So while pulling my kid around on a sledge in the snow I eventually burned up the motor wire, causing multiple phase and hall wires to shot.
LCD gave different errors:
01: Throttle Abnormality
03: Motor Hall Signal Abnormality
06: Motor or controller has short circuit Abnormality

I replaced the motor wire, and tested the hall sensors, and they all appears to work fine (they receive a steady ~5V supply, and ~5V comes and goes normally on the signal wires when slowly rotating the wheel).
When i use the throttle, it sometimes shows up on the LCD that throttle is being used, and sometimes not. Motor also just sometimes spin for a split sec, but no speed shows up on LCD.

Thinking it might be a throttle problem, i attempted to use the walk assist function instead, and while it shows walk assist is activated, the wheel spins intermittent, and sometimes not at all (When it doesn't, it does however kick in intermittent again when i spin the wheel manually).

Edit: I also tried PAS, but that's not responding either, on either of the controllers.

I thought i must have fried the controller, so I then replaced the controller with a previously used KT controller, but the problem remains the same.

So then the question is, is it likely that the LCD3 and/or throttle could be broken, or could it still be a simple hall sensor issue (since it does not register speed, and it kicks in intermittentlywhen walk mode is activated and when spinning the wheel by hand)?

I've uploaded a video of the issue here: https://youtu.be/LQ7aSn9Ger8

What happens when you twist the throttle while manually turning the wheel?

Thank you for the reply, I've tested it now. If holding throttle while spinning the wheel, it works intermittently, same as walk mode. It does however throw error 1 at me constantly, which is throttle abnormality, but it also did throw errors 3 once, which is hall.

I think i will try to replace the throttle first with a spare and see what happens, but to me it looks like there still is an issue with the hall sensors, even though they measured ok. Unless its the lcd3 thats just reading them wrong (although i thought this was all handled by the controller only?)

Jan-Erik-86 said:

Thank you for the reply, I've tested it now. If holding throttle while spinning the wheel, it works intermittently, same as walk mode. It does however throw error 1 at me constantly, which is throttle abnormality, but it also did throw errors 3 once, which is hall.

I think i will try to replace the throttle first with a spare and see what happens, but to me it looks like there still is an issue with the hall sensors, even though they measured ok. Unless its the lcd3 thats just reading them wrong (although i thought this was all handled by the controller only?)

Click to expand...

Could be the 5V supply was damaged in some way since throttle, halls and PAS rely on that. if you could measure that while testing the motor, it might provide a clue, especially if it doesn't maintain a constant 5V.

Thank you for the tip, i will check it and report back.

I checked the 5V supply and noticed it was indeed very unstable when spinning the wheel, but also while spinning it by hand, so something was obviously at fault inside the motor. I took it apart again and retested all the sensors and they were indeed fine, but i did located the issue quite fast afterwards though. The circuit board for the sensors were simply not strapped down tight enough and were touching the outer cover of the motor causing an intermittent short.
Also added some kapton tape to give a bit of extra protection.

Motor and both controllers are working perfectly fine again now.