Starter Wiring ?

I apologize in advance for asking this question again but I think it got buried in my last thread on the subject. I'm still curious about the wire shown in the FPM wiring schematic that goes from the starter to the alternator. With the exception of the wire directly to the battery and another to the ignition switch my wiring is set up differntly in that one wire goes back to the ammeter. Any ideas on the reason for the difference? Also, could someone explain to me how the "R" terminal on the Delco starter helps the starter to function better?

 

OK, how about this explanation. The ammeter connection is for sensing current draw from the starter motor. It's probably unique to the early Renegades. The wire shown going to the alternator in the FPM is still a mystery though. As for the "R" terminal on the Delco starter, this provides full voltage to the coil for easier starting. 66cj5 mentioned this before but I was thinking in terms of some input voltage to the starter not voltage supplied by the starter.