testing the stepper motor

edd001 · Post by **edd001** » 08 Feb 2004, 17:24

hi
just gone to test stepper motor and noticed that it has four pins.
dose anyone know which pins I use to test the ohms reading.
cheers edd

AndersDK · Post by **AndersDK** » 08 Feb 2004, 17:51

As I understand it the stepper motor got at least 2 stator windings & a rotor winding.
If not - it would'nt be a stepper motor - but simply a motor.
I'd expect in the vicinity of (maybe a couple) 100 ohms. Obviously not shorted or disrupted.
I suspect these motors fails by dirt in their mechanicals - making them stick.

edd001 · Post by **edd001** » 08 Feb 2004, 18:33

cheers for that but which pins do i use

AndersDK · Post by **AndersDK** » 08 Feb 2004, 19:45

I'd expect one of the pins to be a common - the other 3 then have some sanely ohm readings to this.

alexx · Post by **alexx** » 13 Feb 2004, 19:11

Some additional info on this subject, taken from 'Revue technique - Peugeot 306', hopefully applicable to Citroen (1.8 and 2.0 engines):
On Magneti Mareli 8P and Bosch MP5.2 fuel injection, idle stepper motor has 2 windings, one connected to pins A and D, and other, connected to pins B and C. For MM8P, resistance 55 Ohms is specified, both on A-D and B-C. No specification for MP5.2 idle motor.
On Sagem SL96 and Magneti Mareli 1AP fuel injection, 'idle stepper motor' seems to be an ordinary motor, connected to pins A and B, with additional position switch, connected to pins C and D.