I have a diesel with the double battery balance system (for cornering). Just curious as I add a winch if it matters which of the 2 I attach the leads to, I would think it would make a differnce on a diesel but......

 

I'd use the easiest one to get to....LOL. But seriously I don't think it would matter. I'd use the one on the driver's side.

 

Ditto what Bud said about the drivers side and there tends to be no other wires connected to that battery.

 

HMMMMMMMM...I wonder how a guy from Colorado found the Massachusetts Chapter to post his question??? My suggestion to you is that you find the tech threads for the truck you're talking about and ask the question there...you'll find lots of help I'm sure. Good luck...and...welcome to FTE!!!