94 civic 1.5L - alt wire melted?

Why would the main wire melt the terminal post on an alternator that is only
in use for a couple hundred miles? Could it be the internal regulator
failed causing the overheating?

 

Wire was loose and arcing. Or really, really dirty.

Was the alternator overcharging?

 

When AAA arrived, they said the alternator had very low output. The battery
tested at 11.8volts, then with headlights on, it dropped to 10.8 quickly and
was slowly dropping more, so they flatbedded the car home...now that I think
back, I did smell burning plastic days before the car died.

Any comments on the value of adding a volt meter vs an ammeter?
The factory idiot light was useless.

 

The idoit light controlled by the voltage regulator is the most simple
and effective tool. However, if you are using a voltmeter or an ammeter,
you'll have to use some brain power to determine if the charger is at fault.
Someone borrows your car could get stranded. Plus, one more part to fail.

 

Probably high resistance on the solder.

Protect your voltage regulator. Don't use your alternator to charge
a dead battery or a battery that never seems to be charged. It's
designed to keep the battery topped off. Don't use a hair blow
dryer while driving, or run the AC fan continuously.

 

You are correct - I had replaced a worn out positive battery terminal a week
or two afo and now it has rusted!
I need to clean the terminal and the wires I clamped into it and appliy some
grease to protect it.

 

Obviously, there're no solder connection. Typo, meant
terminal connection, not solder.