Motor cutting out/making clicking sound?

Hey guys! Just finished a new build and I’m running into a bizarre issue that I believe is stemming from the hall sensor connection between my BKB 6374 and my FSESC 6.6 (running in FOC). Here’s what has happened the past 6 times I’ve attached the enclosure to go for a ride:

  • Test spin motor before going out on the road, everything seems fine.
  • Put the board down on the road and start riding, everything seems ok.
  • After going over some bumps, the motor will stop functioning correctly and will begin to make this clicking sound:

Every time this happens, I go home and take the enclosure off to try and troubleshoot. What I noticed at first was that the hall sensor cable going into my FSESC was very loose, so I tried direct soldering some wire to the connector’s pads and attaching the sensor wire with two MR30 connectors. This seemed to make things run a little more consistently, but the problem still remains. I’ve tried recalibrating the ESC using the VESC tool many times now. I’ve also tried switching the sensor voltage between 5v and 3.3v to see if it made a difference. No dice. The ESC is not hot, and the motor is never overheating.

The only thing I can think of is that the sensor cable in my BKB 6374 has gone bad, or maybe the hall sensor itself. My next plan is to open up the motor and try swapping all 6 of wires connected to the hall sensor with fresh silicone wire, but I’d love to hear what others might have to say about this problem. Maybe one of the hall sensor traces in my ESC has gone bad?

Any help is appreciated!

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  1. Try setup & run the motor in sensorless foc mode, this will isolate / determine if the sensor is at fault. Or simply disconnect the sensor wires completely.
  2. Try another ESC if you have one? that will isolate the fault to the motor or ESC.
  3. Check the motor for internal short, you can do this by hand, disconnect all the phase wires & remove the belt from the motor pulley so the motor is isolated from the drive train. Rotate the motor in your hand, be sure the phase wires are not touching, feel for any resistance. The motor should spin freely.
  4. Remove the heat shrink from phase wires & Check the quality of soldering on the motor & ESC connectors. Cold solder joint can cause this problem.



Hey! Thanks for the good ideas.

  1. Sensorless mode seems to work fine, but I’m going to continue to try and get the sensor working for a smoother motor start-up.
  2. No spare esc :frowning:
  3. Good call! No internal short.
  4. Solder Joints are good!

Going to take apart the motor and look for problems with the sensor cable. I’ll keep this thread updated as I find out more.