Finally was nagged into replacing the wiring harness on my girlfriend's 82 242T today. While I was looking at the extent of the harness decay, I noticed that the alternator (the original 55amp) was starting to squeal and she mentioned some strange electrical issues that could have either been attributed to a bad ground (harness) or a failing alternator.

So I took an alternator I had from an 89 or so 240 and had it rebuilt (now 90 amp) and planned on putting it into the turbo. The same guy has rebuilt 2 other alternators for me with good luck so far. I had forgotten about the extra post/nut on some of the newer alternators. Since my 86 is in the shop for a smog and I can't compare the wiring on that (I seem to remember it has an extra post), can anybody advise how to wire this now?

B+ (10mm nut) gets the big red wire
D+ (spade) gets the little red wire
Ground (8mm nut on the edge of the housing) gets the blue ground wire

What should I do with the extra post that seems to be equidistant to the D+ stamp on the housing (another 10mm nut)? I left it unhooked and the moment everything was wired back up, I got the alternator failure light on the dash and no charge.

I double-checked all other ground points and connections for the new harness and it is a clean OEM replacement harness (dark grey connector). Car turns over fine and runs better than before, just no charge.

I will enjoy a frosty cold beverage in hope of enlightenment. Thanx.