1972 C10 350 Charging Issue

[Bryon.Dillon]

I dont know whats going on here, but my battery keeps getting drained to the point where I cant start my truck. I replaced the battery a week ago trying to solve the issue and it seemed to do the trick, until this morning I went out to start it and it didnt have enough juice. So naturally I assume it's the alternator, so I bring it in and have it tested at autozone. They tell me it's good and is charging 14.6v. So I buy a new voltage regulator, and install that in my truck. Heres the weird thing, if I start my truck and check the voltage coming from the red wire on the back of the alternator, its at 12.6v... i get the same reading on the battery, it seems to fluctuate between 12.6v and 13.10v depending on how long i let it run after jumping it. I'm seriously stumped, I have cleaned the battery cables and the ground to the engine. Tested all the wires going from the positive distribution block and they are putting out the same voltage as the batter post. What else could be wrong?