My Goddaughter's in Tucson with her '70 Duster 318; I'm in San Diego.

She called today saying her battery isn't charging. Her aftermarket in-dash volt meter reads 11 volts with the motor running.

Long story short, she found the battery stud on the back of the dual field alternator has somehow snapped off and the wire was just hanging loose.

Ok, so her local Autozone has a single field alt in stock. She gets it swapped out and doesn't know which field wire to hook up, so I told her she can use either one.

Now at idle she's charging fine, but at cruising speed and up the gauge is almost pegged at over 16+ volts, and she's getting some occasional smoke in the car.

I'm guessing my "either one" advice was wrong? Does it matter? What to do with the unused wire? She's at soccer practice now and she's worried about driving home at night..