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How to find hall sensor wiring when in the dark! Kalkoff/impulse motor

Jan 24, 2023
Hey guys, I have a kalkoff with the impulse mid drive in it, the controller is shot and the battery tired so I plan on just fitting a typical controller box and a 36v battery to make it "work" again, throttle only just for something for my wife to use...
Question is, asides from running it sensorless, how do I determine what is what with the sensor wires? The colours mean nothing in relation to the usual ebike hub world, there's 6 wires and I cannot get into the actual motor itself to find out where they go its a sealed unit... the controller is potted so can't even trace the other end to at least find +5 and -5 to start with!

Thanks all 💪
Wire colors do sort of mean something, just not for mating the wiring order between the motor and the controller. The 6 wire hall plug should have 5 motor hall related conductors, and in your case an additional white wire to support either temperature sensing or speed (more likely speed, since most 36V bikes would run a geared hub, that requires a separate internal speed sensor). The red and black are 5V and ground, so it's important to keep those in the right order, consistent with the controller. All of the other conductors, the 3 big fat blue/yellow/green phase wires and the three smaller blue/yellow/green hall sensor conductors will need to be matched, but not by color.

You can follow Tommycat's guide for making the right matches. Scroll down to the flow chart and get familiar with how it's laid out. It will help getting to the right combination without having to go systematically through the dozen of possible combinations. Ask questions here if you get stuck.

EDIT: Looked up the bike and see it's a Bosch mid drive. It may be more challenging than anticipated, but it may have been done before and worthwhile searching the forum.
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Doesn’t the Impulse motor have a built in controller?

When you say the controller is shot do you mean the display? You can buy a new display but it will be eye watering expensive.

Does the motor look like this?

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