Guys, before I do the BIG 3 I just want to bsure I don't mess up anything. Now my truck already has 2 batteries stock and one is connected to the other + to +. Now the problem will be from the alternator to the batteries. I will need to slice my factory harness to see where all the cables go because they're all in a bundle. Should I just run a 2 gauge wire from the alternator to the batteries and upgrade the ground wires? Or should I dig deeper into my electrical system. btw I'm running 2 of the same batteries AC Delco (650 CCA if I'm correct)