I am having charging problem with my 1980 242. I only have 11.50-12.00 at the battery when running. While pulling my alternator off , I found this smaller gauge wire connector that was spade connected to something in the center of the internal part of the alternator. I cannot remember if this goes to ground or to an idiot lite or something, but I cannot find the orig. wire that was connected to it, so do I run it to ground? This is the old external voltage reg.model. There are two heavy cables, one + and one- and then this third one that I can't remember where it goes.... I may try swapping it for an internal regulator model, but the jury is still out on that because there is a third wire on that one too, but one guy replied to my earlier post and said it will work.

This is for the alternator with the internal regulator. there should be a small red wire that comes out of the engine harness with the oil pressure gauge wire. It comes from the "amp" dash light. It plugs into the spade, and it is not a ground. From my understanding it provides the seed voltage to get the alternator started. The alternator should be grounded, usually by a short wire going from one of the nuts holding the alternator case together to a bolt on the alternator bracket. The only other wire is the big red one that runs from a nut on the back of the alternator to the starter motor (another red wire runs from the starter moter to the battery). You can identify the nut on the back of the alternator because it is insulated from the rest of the alternator with a non-conductive washer of some kind.
I can't remember the external reg setup, since I have not seen one for years.