Alternator and related wiring

[Foghorn]

First, thanks in advance for taking the time to read my long-winded post!

Since owning my car I have had repeated alternator issues. The battery light would come on and shortly thereafter, the battery would not maintain a charges. On three separate alternators, the output post would get so hot that it would melt the plastic insulator. I finally threw in the towel during a separate project of swapping the OEM iron shortblock for one based on a Teksid and rewire the whole thing, to include moving the battery to the trunk.

Car is running again, but battery isn't charging. I metered the wires and discovered that there was no voltage on the voltage regulator reference wire (Yellow/white stripe). I have since traced that wire back to the engine compartment fuse box and located which fuse protects that circuit. Checked the continuity from the fuse all the way down to the alternator plug, which is good.

Now for my question: I can't figure out how the power gets from the battery power input post on the front of the fuse box to the other side of the fused circuit. I don't get 12v on that side of the fuse and there is no continuity between it and the power input post. Is there a relay controlling this so the alternator field isn't powered full time? I've checked with the key in the run position and still get no continuity. Lastly, could a loose connection somewhere in this circuit cause an overload on the alternator which in turn causes the output post to get so hot?

Thanks again, this site has helped me tremendously! You guys are true experts...

 

[Foghorn]

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Any tech assist would be greatly appreciated.

 

[Foghorn]

I finally just dug into the underhood fuse box and followed the wires from the alternator harness. I had to get the box dismounted from the strut tower and then remove the bottom of the box itself. Not technical at all, just delicate work if you don't want to break the plastic tabs holding it all together. Depending on your individual height & flexibility, this could be more of a challenge for some than others.

So, in the stock wiring harness for the alternator the heavy duty wires (gauge 8 or so) that run from the alternator output to the power in post on the underhood fuse box, there is a light green pigtail that goes to a 4-way plug that also houses the yellow/white stripe wire which is the field wire for the internal voltage regulator. This light green wire provides the 12V through the fuse box to the yellow/white stripe wire. It is protected with a 20A mini-fuse.

As part of my rewire, I replaced these gauge 8 wires with a 4 gauge and terminated the light green wire with a ring terminal that now mounts on the power input post.

Turns out that all of my wiring was correct, I just had a bad alternator. Please advise if anyone needs any clarification.