In preparation for buying a new 5er, I just bought a 2011 Silverado 2500 diesel. It came with two batteries and dual 125 amp alternators. It seems a shame to waste all that capacity, but the wires in the standard harness are much too small to make much use of it.

Is there a convenient way to use more of that 250 amps to charge the house batteries? If I were to connect a second, heavier wire, where do I connect it it in the truck? Does it make a difference which alternator I hook to?

Thanks,
Joel