Vintage Cars: starter connectio0ns, gm service manual, motor windings

Question
I have had bad luck with starters and batteries in the past 3 years and I believe that I might6 have had the connections wrong.  The car is a 68 GTO.  There are 3 wires goiong to the starter, two to the positive and one to the "s" side, what goes to the "r" side. The two that go to the positive are, one from the battery and the other one from the main breaker of the wiring system.  The car has been completely rewired.  I have a GM service manual but it doesn't really say where the two wires go in conjunction to the markings on the starter, other than the main positive from the battery.

Answer
I do not have the electrical knowledge you will need, but a little research brought this up on the web, it was in a FAQ but I don't have any idea of the skill of the poster, but it might answer your question.

You could also try one of the other experts here.

Q:     Starter Wire
   Does the purple 12 ga wire from the wiring harness to the starter go to the "R" terminal or the "S" terminal on the starter? and what is the other terminal for?

A:   The 12 gauge purple wire goes from the starter switch, through the firewall plug harness, then down to the "S" terminal of the starter. The "S" terminal serves to actuate the starter SOLENOID windings. When the solenoid pulls the starter drive to engage the starter, it also closes a couple contacts via a disc on the solenoid assembly. This energizes the starter motor windings and turns the starter. The other contact that is made with this disc is the "R" terminal (Relay). This terminal supplies a "direct" path to the ignition coil positive terminal while the starter is energized. The reason for this dedicated path is to maximize coil current while the starter is "taxing" the system, i.e., creating a voltage drop. When the engine starts and the starter switch is released, the "R" terminal is disconnected. The ignition coil then continues to be energized via the ignition switch loop and the resistance wire. I have diagrams if you need them.