No + voltage at B terminal on alternator!
 

The SA suddenly has lost it's Positive voltage at the B Terminal post on the alternator side. It's currently running an S5 alt too, so now there's a huge drain on the battery.

I'm currently just running a jumper from the positive battery post directly too the alternator's B terminal. This lets the car run, but the battery still gets drained after a cold night.

And just to be sure, the Black wire with the eyelet that bolts onto the Alt's B Terminal should see a 12 v+ with the car off, right?

And what is likely to be the cause of the wire not having voltage? I need some help on this pretty badly.

The B terminal should have voltage even when turned off. It is a direct connection to the battery's Positive post. If you do not have voltage, then you have a bad wire somewhere. Start tracing. I don't believe the stock wiring has a fuse in there, but who knows for sure. Maybe a burned up thermal link if you still have them.

You've blown the main fusible link.

I have no fusible links. I put the FC fuse block in and the fuses all show good still. NOt sure what's going on. I'll have to just start tracing I get?

And by thermal link did you mean fusible link?