So, I'm upgrading the alternator on my 81 300SD (617.951 126.120) to 120amps and am using this http://www.peachparts.com/shopforum/diesel-discussion/93569-alternator-115-amp-bosch-al129x-works-123s-post2010773.html?highlight=wire#post2010773 as a guideline, but I've got some questions, and I don't want to get my wires crossed (I know... I'm sorry). My reason for the upgrade is better charging for short trips and better starting in Winter.

I removed the battery to starter, starter to junction, and alt to junction cables today. In the junction the right 2 spots have a band connecting them. I can't tell but am guessing that this is conductive and connects those two terminals because I can't remember if there was one or two wire on the term where the alt connected to the junction. If there was one, then that would make sense to me. If there were two, then I've lost something in the garage. What is that smaller wire from junction to starter? A ground or something to do with the dash light? That'll get replaced too.

Here's my main question. In the previously mentioned post, they wire the alt directly to the battery. Would that be in addition to all of the other connections going back where they originally were, or is it in place of a connection somewhere?

I guess I'm wondering if there is any reason to bypass the junction and why/how. I'm getting the feeling it's more of a swap job than a rewire, which I thought it was going to be.

btw, I am using 2ga for everything except for the body ground to engine ground which is 4ga cause that's all I could find today.

I hope that was clear enough. Thanks for reading!

~bri