"Overvoltage"
 

Alright guys, this one's really got me scratching my head. Today while driving the car I noticed that the voltmeter was dancing a bit between 13-15 volts. It got worse as I drove throughout the day, so I decided to stop by my buddy's shop.
Guessing that the voltage regulator was out on the alternator (8 years old at this point), I replaced the alternator. No change.

I can't possibly believe that 2 different alternators could have a bad regulator... the voltage spiking was so bad that my interior lights and headlights would get bright as the voltmeter hit 18!!!!! Has anyone seen this issue before? I'm really not sure where to start.

Here's some video of it at idle.

https://www.youtube.com/watch?v=jcFR...ature=youtu.be

Re: "Overvoltage"
 

The regulator regulates the voltage at one of the wires in the plug (IIRC the red wire). This is not to be confused with the heavy wire (stock in black) sending the current to the battery. If the there is a fault in that "sensing" wire, the alternator is not seeing the same voltage as the rest of the system.

Looking at the wiring diagram from AustinThirdGen, alternator at lower center, if the fuseable link got partly fried, it could be providing variable voltage to the alternator's regulator.
http://austinthirdgen.org/mkportal/m..._continued.gif

Re: "Overvoltage"
 

I'll be checking that out tomorrow morning. Thanks for pointing me in the right direction.