My alternator died so after perusing Ebay for something cheap I decided on a Ford Taurus alternator that would give more amps. It's a 4G model that has a D-shaped three-wire plug/harness affair in addition to the B+ terminal and the Ground. Said wires are marked "A", "S" and "I" on the D-plug.

I assumed that the "I" wire should connect to the small red exciter wire and that "A" would go with B+ (Big Red).

I got the thing to fit (a bandsaw helps) and installed it and plugged the wires in and cranked the car. The battery light on the dash went out-- a good sign I thought, but my multimeter read a disappointing 12.8 volts between battery terminals that diminished as the car ran.

Does anyone know anything about these Ford alternators and offer advice about this installation? Have I screwed up the wiring? In the meantime I
l'll report back.

I'm open to suggestions of other alternators that put out 125 amps or more; I picked the Taurus model thinking they'd be plentiful and reasonably easy to adapt. Besides, it wasn't a GM.