alternator self exciting?

[s50b30]

I am missing the plug for the alternator to my mkiv.

Just wondering if it will self excite above a set rpm?

I remember someone told me that some alternators do that.

 

If I can do without the voltage sense etc, that would be great.

 

I also saw someone just put wires from the big 12v post on the alt, to the three pins on alt plug.

How will that work? Battery drain?