MicroSquirt.com read only forum (Jan.15,2018)

I have a hall sensor that uses a magnet to trigger it. It has three wires going to it, red ,black and white with white being the trigger. I have the Opt + wire going to the white wire and the Opt- wire going to ground. The voltage is 5 volts from the white to the red wire. When the magnet goes by the sensor ,the voltage goes up to maybe 5.6 on a multimeter. If I read the manual correctly the ECM needs to see a reading that goes to zero and back up. What do I need to try next? I ran 12 volts to the sensor and it had a baseline of 12.3 volts between the red and white wire and when the magnet goes by the voltage goes up to 13.04. The ignition is a sealed unit on a two cycle model airplane engine , so I cant open it up to get to the negative side of the coil to try that input. Any help would be appreciated.

Thanks,
Lance

My hall sensor is a 12 volt unit. Matt Cramer at DIYAutoTune suggested I wire the opto+ to +12 through a 470 ohm resistor and opto- directly to the trigger wire. I used a 1k ohm (didn't have a 470) and I am getting a crank signal.

Thanks, I will give that a try.