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

[Le TVR]

Stepper motors dont work like normal (dc) motors. They need phased pulses that are synchronised to each of the coils to make them move.

The ECU provides such phased ac signals but a battery cannot.

[sotonS2]

Be careful here - aren't most ECU signals only 5v ? Might be worth checking before you fry the internals.

[feithv8s]

Thanks, I'll better be careful !