How to test the stepper on the bench???

[hiltonig]

Is it possible do connecting a supply to one coil or the other ? It's on a after market ecu, the car isn't ideling right, stepper is fully open but there is 12v present on one set of coils, it doesn't move, of course it could be on the wrong set. Anyone get any info on which coil drives in what direction ?


Cheers

[blitzracing]

Its not a case of what coil goes which way, its the sequence the coils are switched to make it rotate one way or the other. In its stopped position there is a static voltage on the coils (how many I dont know)to hold the motor in position. You can test the switching of the coils using an LED and resistor so it will run at 12 volts. If you put the LED across any pair sequential of connectors you will see it flash when the motor rotates. I cant remember the polarity off the top of my head, but if you get it wrong the LED simply wont light.