Alternator Wires Melted, What did I do Wrong? Options

[newto914s]

We, my father and I, were in the process of changing the alternator (the old one froze) http://www.914world.com/bbs2/index.php?act...81&hl=newto914s

We got a rebuilt from autozone, but after putting it in we figured out it had a bad diode(never go to autozone). I ordered another one from a place online I get a lot of parts for my old Benz from. It was cheap. $80 for a bosch rebuild + 20 core charge, they have free shipping, and I usually receive my order the day after I place it(crazy fast).
Now I wasn’t there for this, but after my Dad reinstalled the alternator when reconnected the Battery cables the wire harness on the altenator started to fried. By the time he got the wire off the battery again it had completely melted the wire going from the Alt. to the starter, and singed the wires going to the relay board.
What might have caused this? I already ordered a new harness from Jeff, but after I change it I don’t want to melt another one.
Could it be the wrong amp Alt. It’s a 55 amp
Oh, 1.8 block with D-jet
Thanks guys
Samson

[davep]

As much as anything else, the thing to look for is a burn spot. I would look on the inside of the duct/cover. The cover is bolted to the alternator case, and that is grounded through the fan shroud/engine case/tranny case/ground strap/body/and battery ground to the battery. The big red alternator wire goes to the starter, and via the heavy black wire to the battery positive post. Thus, if a stud on the alternator shorts to the cover you will have a good arc-welding circuit. In this case the weak link is the heavy red wire to the starter.

This has certainly happened before with rebuilds. Clearancing the stud to the cover is the only solution. I'll try to provide a stud height measurement when I get home tonight.