Alternator from 06-07 B9 Tribeca - 3pin connector?

[Legacy777]

More than likely, you're looking at the wrong wire. That wire is the one that goes to the starter.

There is one on the manifold....that is the one I'm talking about.

[free5ty1e]

Ah, then I still havent found this grounding point yet... I thought I had finally found it with the photos I could find of it but im confused again lol.

Ill post if I find it

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[Legacy777]

If you take some pictures of a wire in question i can tell you whether that's it or not.

[free5ty1e]

OK, thanks -- I will probably be able to get a good look in the '92 in the near future as it will be quite apart in my garage for a timing belt / seals and valve cover gaskets. Perhaps I'll be able to find this hidden ground then!

[ciper]

Alternator on my 91ss died today, this post made it easy to convert into a used 2012 STi alternator I had. The only significant change was to drill out the main power connector since the old alternator was m6 while the new alternator was m8. Only the sense and light wires were used. I'll replace the plug eventually but was able to temporarily wire it in like so -

Thanks guys, indeed between your two posts I think I got it figured out.

I have confirmed this came out of a 2006-2007 Subaru B9 Tribeca, but it doesn't appear to matter. Both have the same 3-pin wiring as far as I can tell.

Furthermore, the following two links show the connector's wiring in very simple diagrams in the upper right hand corners:
Legacy alternator - 70 Amp
Newer Subaru alternator - 90 Amp (awesome)

More specifically, here are the two little connector diagrams that show the pinouts: (edit - NOTE --- these are for the MALE connectors on the alternators themselves, not for the FEMALE connectors on the harness. If you are attempting to wire pigtails up, keep this in mind!!)
Legacy alternator 4-pin connector (#351):
Newer Subaru alternator 3-pin connector (#319):

So, it looks to me like I can actually wire in both plugs to my harness so my '92 Legacy Autotragic supports either style alternator. Is there any reason I should not do this (tap and solder) and instead should lop off the Legacy 4-pin connector and solder on only the newer 3-pin connector?

Also, kinda curious what the wires actually are for, tried looking at wiring diagram and it wasn't readily apparent (I need to get better at reading automotive wiring diagrams). Obviously the "IG" is for ignition, although I can't see why it would be needed. D? S? L? Then, as mentioned earlier, the big bolt is a +12V out directly to the battery and NOT a ground, correct? The alternator grounds through the mounting bracket? (and should I slip a ring terminal in there to run a new ground to the battery along with the other grounding mod points I'm aware of?)