Ok I had a electrical problem(posted in troubleshooting forum), I found out my alternator was bad, so im getting a rebuilt 100 amp to replace it,(i will be running a sound system eventually so thats why i went with 100 amps) and my starter is going to be rebuilt also. My question is about the wiring from the firewall to the starter and alternator. In my 79Z there is one wire coming from the firewall, I think its black, and it joins with 4 others near the middle of the firewall, they're red and 2 ran to the alternator, one to the starter and one wasnt being used it had a clip on it, and my question is if its supposed to be like this? If anyone could post pictures of theres i would aprreciate it.
Sorry for such a long post but i wanted to be thorough. Thanks everyone.

There should be 2 wires going down to the starter. 1 - red large wire & 1 - black smaller wire. The large one connects to the big post on the starter solenoid, and the smaller one to the small post on the solenoid. You should have 3 wires running to the alternator...2 on a plug-in and 1 large red one that attaches to a post on the backside of the alternator.

Ok, so what should i do with the extra wire that i have? Also do they form into one wire near the middle of the firewall?