Si 12 install help with plug ID thanks VetteVette

[conoco]

Just installed my 100 amp si12 and everything is great and working. I decided to clean up and retape the wire loom while I was at it. When I finally got the tape off I noticed this plug that was taped up with everything. I can't seem to locate it on my wiring diagram. Any help would be great. I would like to get it hooked back up, it's there for a reason lol. Thanks everyone the Colors to the plug look like black and blue.
On a side note if anyone is thinking about upgrading there alternator to the SI 12 amazon has AC Delco 100amp for 60 dollars. Great reviews. Only bad thing is apparently AC Delco now has there stuff made in China like everyone one. So let's see if it lasts lol.

Thanks VetteVette for an awesome post on the conversion I found. Everything went smooth and your way of doing it was way better and cleaner than the others.