I have a 67 Chrysler Newport, I recently replaced the alternator with an OEM 55 amp alternator, and voltage regulator but it's only reading 11 volts. I've checked all my grounds, and I don't appear to have any parasitic draws on the battery. It slowly gets weaker and after about a week of being driven it'll kill an 850 CCA battery. This is my second replacement alternator, and I've checked most of my wiring off the positive cable and it seems to be good without a bunch of corrosion. What am I missing here?