In your case (because you have the 70 and up regulator and the 2 field connection alternator) the relay feeds both the ignition and one field of the alternator. The second field is connected to the field connection on the regulator.
So by feeding batt voltage from the relay to the ignition wire, I am also feeding the regulator thru the ignition terminal, blue, as well as the blue wire going to alternator field.
