i just got a new battery and a new alternator not even 2 weeks ago and now my volt meeter is reading below 12 when it should be between 12 and 14 even when the light and radio are on. i was wondering if it could be a ground wire that is lose or not connected ? i called around and some people said that it just could be my alternator because its "after market" (not OEM) ? dose anyone know what is going on?