[BrentBTK]

Thanks a bunch. Attached are a few pics of the back of the alternator. It's a mess. The brown wire coming out of the plug on the back of the alternator goes to some janky plug. The ground wire goes to the chassis, and the red wire goes to that same janky plug on a 3 way splice from the battery, to the alternator, and I think into the cab. The spliced in plug goes nowhere...

Edit* After looking through some videos, it looks like the "janky" plug used to go to an external regulator. Do I take this to mean it's internally regulated, or is that the problem?