Hello all, Looking to hear from someone who has done the big 3 upgrade on a 2009 duramax. I have a couple questions. I have done big 3 upgrades on a few other vehicles which had alot less going on under the hood making it all a no brainer. Now being that this truck has 2 batteries and 2 alternators im just curious if big 3 turns into big 6 lol. Do each battery need to have - to block as well as + to each alternator? As well as block to chassis? Im not looking to cut any corners I want it done right im just not sure if your supposed to do each battery and each alternator or if one is fine being that it is in paralell. I have searched everything I can find online and theres very little info. I know theres also a voltage regulator that is supposed to be on top of the ground wires that tells the alternator when and how much to charge (apparently a gm thing). I do not see this unit on the drive side near the battery like I seen online. Is it possible this truck does not have one or mayby I was looking at an older model online. Also I read from one user not to do any positive leads due to to many amps travelling through the path of least resistance and possibly frying some cables? Never heard of something like this before. Ive read to leave all oem cables in place and just do a second run. Anyone that has done big 3 on a duramax please lemme know how you did yours and if you have had any issues... Thanks for reading!