testing voltage regulator

ok im having charging issues...none is the issue...let me start with what all i have going on under the hood...72 dodge demon 340 optima red top battery have a msd 6al, msd blaster 2 coil oem voltage regulator and have the mad set up for my ammeter. ok whlie running...have to jump it off...im getting 12.4 volts at battery(positive-neg terminal).. from neg terminal- blue wire (which i think is ign 1) 12.4 vltz. from neg terminal- green wire ( should be ign 2) i am getting 4.4 vltz) i have had the alternator checked and it is good. when i noticed it not charging i had it checked then went to the voltage reg and noticed that it was loose from the fire wall one of the screws backed out so i took it off and wire brushed the case and fire wall to create a better ground and its still doing the same thing. is it possible that with it becomming ungrounded it could of damaged the voltage regulator