Overcharging problems

The blue wire going to the voltage regulator is probably your issue. All the blue wires under the hood are connected together near the master cylinder in the harness.

Follow it from the ballast resister and it will lead you to a solder joint where they are all connected. I believe that may be your problem.

Somewhere you are losing power to the voltage regulator. That is the wire that controls the charging from the alternator. Fix that wire and your problems should be corrected. That would be the first place I would look.