TESTING STEPPER MOTOR WITH 12 V BATTERY

[feithv8s]

I have taken the stepper motor of my V8S out for testing as setting idle is quite bad.
The stepper motor has two coils, I think to give more or less valve opening.
Two coils with each two connections: resistance acc. the bible is OK.

My question: is it possible to see the stepper motor actually working when taken out and just connecting 2 pins to a 12V battery?
I tried, heard a very very soft click, but did not see the valve moving.

What signals are coming from the ECU?

Regards,
André Feith
V8S

[briantvr350i]

André,

Wouldn't recommend this at all, most stepper motors work on pulses of 5 volts or so...

Not 100% sure about vehicle versions, but more than likely still driven by pulses.

12 volts may damage it permanently.

Regards,

Brian (and a Red350i)

[jchase]

Don't know about this particular stepper motor, but in other stepper motors you alternately actuate each coil, which will move the shaft around by a few degrees. So if you are patient, and you connect the terminals up one after the other you should see after about 20 times the shaft has moved around, perhaps by as much as 90 degrees!

Sometimes it will say how many degrees each step is on the case. E.G. 6 degrees/step will mean you will need to cycle the coils 60 times to get one revolution of the shaft. If you use a low wattage 12v bulb IN SERIES when you activate the coils, you shouldn't melt the coils inside. The bulb works better for inductive loads than a resistor. (I take no resposibility if it blows up though!

-Jim