[HO455]

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

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?

You have installed a voltmeter and disconnected your amp meter?

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.