Please help Me.."Overcharging"?

67Dart273
I don't know if you caught my last post. It was on the prior page...I put.

Its at 14.50 right now.
With the green wire off, it slowly goes down hill, as in 13.8 and goes down slowly even lower.
The odd thing is, it can be fine for an hour, then start overcharging out of nowhere, and go back to normal.
Without moving the car or bumping anything.
I just find it odd I did not have this problem until I changed the ALT due to a broken pulley.
It was just a broken pulley, was charging fine before the swap.