My "new" '72 is acting alot like my dead '71 used to. At normal speeds, everything's fine. But at an idle it seems like the voltage is really low. The first thing you notice is the turn signals blink really slow. If the headlights are on, the signals are like maybe 4 seconds per flash. Is this just 'the way it is' with a 240, or do I need a regulator, or do I maybe have some burned out diodes in the alternator?