I have a 250W 36V brushless motor and I want to check that the hall effect sensors are functioning. I read on this site that it is possible to use the diode setting on a multimeter to detect the on/off state of a hall effect sensor. They said put the red lead on the sensor wire and the black lead on earth.
Am I correct in assuming that the black wire in the sensor socket is earth? I tried that and turned the wheel and could not get a low voltage reading which I would expect when the sensor conducts due to the presence of a permanent magnet near it.
I am also puzzled about the role of the red wire if the sensor is merely a magnetically activated diode... Maybe someone could draw a circuit diagram or how the red, black and sensor wires connect to the sensor... is there a pull-up resistor in there or what?
Please enlighten me about the sensor circuit and how to test it.