I have a 2009 pontiac g6 gt and my car will not start and I am trying to figure out why. Over the past few years I have replaced both the alternator and battery twice, and they both keep failing at some point. Right now my battery is at 4 volts and there is nothing when I turn the key. I have changed my negative battery wires as well as changed the wire lead to the alternator, that was previously melting. So I figured I have some kind of short, I just don't know where to look, and how I should fix the problem, or even if it is worth fixing.