You're on your own with that. The Acadia cable appears to go from the + terminal under the hood, though a grommet, behind the firewall, and into a relatively twisted path inside the body to the battery box (see part 7 on the diagram). Looks like it would be too much of a hassle to get a fish down the path so you can pull the the cable through. Plus, there's probably not enough room to run your cable beside the stock cable through the firewall grommet. Why not put a hole with weather-proofing (grommet or other sealant) into the battery box and run your cable from the battery box, beneath the car along a support rail, and in front of the firewall up to the + terminal?

http://www.tonkinonlineparts.com/showAssembly.aspx?ukey_assembly=808235&ukey_make=1088&ukey_model=15685

 

I concur. That's the same diagram I have.
I was hoping someone would know of any panel that once removed, would expose the routing.
Drill and tuck is certainly an option, just hoped not to have to make any new holes.

Thanks.

 

If you're real good at removing/refitting carpet, trim and such, you could probably find the positive cable's pathway through the body and fish your cable through that path in steps starting at the battery. An extra set of hands would likely be most helpful while doing this. Then, you'd still be faced with getting the cable through the firewall.

Your car is still under warranty, right? Remember that any problem which could remotely be determined to have occurred as a result of your work might void that warranty.

 

Yes sir, you're spot on about voiding the warranty. That's why I'm in the "no hole" mode.
Getting to the firewall is 95% of the problem. There are a couple of holes that I can get through the firewall at.
The center console is passable but getting from the box to it appears to be closed.
I think this is a "and this too shall pass" situation.

 

From the diagram it appears that if there's any place to 'take a peek' at the positive cable routing, it would be under/near the sill panel of the RF door.