fix uncovers another problem

Yesterday I finally decide to replace my alternator

I go to get a new one and talkin to the guy he says its the regulator, so I buy the regulator, get gome and start to install it and notice the wires are cut, 2 are bypassed. He had been running it straight with no regulator!

So Im thinking mebbe he had replaced the alternator with one with an internal regulator so I take the alternator up and the guy says its correct and we decide to test it. IT WAS PUTTING OUT 30 VOLTS! No wonder it was boiling batteries.

Anyways, while takin everything apart I notice that the bottom bolt for the alternator is like 1/16 in diameter so I need to replace it but the thing that bugs me is that whether the car is on or off I stil get a voltage reading inside the car, its not supposed to do that is it?