Voltage Regulator Question

[Gianyveedub]

Thank you for all the replies. I should go into more detail about what I have and where I bought it. The truck has an HEI distributor ( I know someone mentioned electronic Ignition) and the alternator was bought at Winchester Auto (I had taken it back and got a new one free of charge and took the "new" one to AutoZone where they said it passed). The battery and regulator (type 1) were bought at Napa. I am just at a loss for words why it would not charge at all until that second ground was added to the alternator. when she is at idle when testing the battery and the alternator, both read 12.0v. I am lost on this issue, HELP...