Hi,i`ve just put an alternator and regulator off an unmolested spares car on my car.

The wiring is sound as i checked for continuity.

The problem is that the regulator is not regulating!

The battery is receiving about 17 volts when revved,which i assume is the max un-regulated voltage for this 28amp alternator.It then drops to 12.7volts when back on idle.

It`s a ducellier regulator, I`ve had the cover off and cleaned the points,but still the same.

Can anyone explain how it functions and what i can do to make it work.

P.S. I`m too mean to just go out and buy a new one without trying to sort this one out!!!