Hey Andy. Thank you for chiming in. I didn't realize that N1 was connected to N2. Looking at the diagrams in this post, I thought N1 post was isolated from N2-N8 of the Z fuse array. Do you know how exactly the N1 is connected to the N2? Is there some sort of relay that's not shown in those diagrams?Hey Dee:
This is what, to use your words, I think you may be missing.
Your main battery is connected to N2, agreed? When the 3.6L JL is at rest, (in fact at all times but an instant at start and ESS events) N2 is connected to N1. I think this is what allows both batteries to be charged when they are connected as per factory, and charger cables are solely connected to the two terminals of the main battery when the vehicle is at rest.
So....at rest, N1 is energized from either or both batteries on the positive side--and in your case solely from the main battery because you've disconnected the ESS/Aux battery, and the other end of your tester is on the negative of the main battery. Stated yet another way, in your situation, N1 IS the positive of the main battery.
Provided your main battery has power, your meter should show voltage resistance.
I think this is the answer. I hope this helps.