altenator STATOR question

[3100 MPFI]

Helping a friend diagnose a problem with the charging system in his Grand Prix, I was looking at the STARTING AND CHARGING SYSTEM diagrams.

I noticed that on the generator (what the book calls it), there is an empty slot at wire postition P that is tapped into the 3rd row of the rectifier bridge (at least, I think that is what it is called).

Why would someone need an outlet to that, and what would it be for? This is just one of those curiosity things, but still..... If I was to add a wire, what would it be for?

[SHOoff]

From what I've found the P is not used.
I'm pretty sure the P is actually for a tach signal.

[3100 MPFI]

I have never seen it used either, but I am just curious as to what it would be used for. How would they get a tach signal from the altenator when there is already one coming from the DIS?

[SHOoff]

That is true. But I believe that the point of it is to be used on a diesel engine, since they will not be able to derive a tach signal from any DIS due to lack of spark plugs.

[3100 MPFI]

ahh. I didn't think about that.