At my wit's end, please help

[Stocker]

Originally Posted by HO455

I would like to verify some of the facts here. First off are you running an alternator and regulator set like pictured below?

This alternator

And this regulator

Now the time line.
Several months back you added new fans and relays to operate them as well a a relay for the compressor clutch. Shortly after that your fusible link failed.

Then several weeks ago you installed a new alternator. And shortly afterwards you had several wires melt down. You said you changed the alternator as it was noisy. The new alternator was an 80 amp unit instead of the factory 62 amp unit shown above. At this time you problems getting the charging system to operate which you solved by swapping several regulators before going back to the old one and adjusting it. The new 80 amp alternator was damaged when the wires melted? It was replaced with another 80 amp alternator?

That's close but a bit out of order, I'll try to set it straight.

The old OEM alternator was noisy and I replaced it with a new 80A unit. At the same time, I added the fans. Shortly after that, the system overcharged and melted wires from the alternator to the regulator. The alternator was thought to be shorted internally so we replaced it with a new identical 80A unit and repaired the melted wiring. System was still overcharging and new regulators didn't fix it. At this point, the old regulator was re-installed and adjusted, and things seemed normal.

Several days later the fusible link blew. I was in traffic and failed to notice if the ammeter showed an excessively high rate of charge. I had been running A/C at the time and after re-attaching the remains of the fusible link, I made it home (well over an hour) without using A/C, just in case that was the problem.

I have since replaced the fusible link and added a relay for the compressor. Still dealing with a too-high rate of charge, which is where we are now.

You have installed a voltmeter and disconnected your amp meter?

No, still running the OEM ammeter.

Firedemon's link to madelectrical will help explain the difference between 1 and 3 wire systems in a coherent manner. That will give you the knowledge to decide which way to go if you are going to change to a newer internal regulated system.

Yes, I have been reading Madelectrical's site. Wealth of information there, for sure.
I have decided to get a 3-wire, 12SI, 94A internally regulated alternator. If I have trouble finding a 94A unit, I'll try for a 100A -- they seem to be fairly common.