AUX battery delete/bypass - Which method is proper?

[Aonarch]

Does anyone know which cable is to my aux battery?

2025 JLUR 2.0

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[AndySpill]

Does anyone know which cable is to my aux battery?

2025 JLUR 2.0

Alex, assuming you have a JL configured with dual AGM batteries, I am sure there are people here who will chime in, based on model year which cable connects to your Aux, it having changed I believe since the JL was first introduced.

That said, I prefer this method:

Start at the body ground connection on the passenger's front panel under the hood. Trace the cable that leads to the main battery's negative post.

It is the other cable on the main battery's negative post whose distal end connects to the Aux battery's negative post.

 

[AndySpill]

This might be a silly question, but has anyone ever had a dealership give them an issue with warranty coverage due to deleting the aux battery/disabling the ESS system?

Respectfully Jack, I think you may be asking the wrong question as it regards whether to not proceed with this change for fear of being denied coverage--much as I doubt such a scenario is all but infrequent to non-existent.

Again, respectfully, I think a more to the point question might be what if that you fear becomes the case? Well, worse case scenario you buy a replacement Aux battery, install it, reconnect the cables, reinstall Fuse 42 and resubmit your vehicle for service.

Of course I can't recommend replacing just one battery without the other...and this gets costly. But I have to think the commonality of this modification, where it to cause a dealer to reject a vehicle for service, let alone all but rarely, would be news already on this forum.

 

[Cartman]

Does anyone know which cable is to my aux battery?

2025 JLUR 2.0

Today I will disconnect this and isolate it.

 

[AndySpill]

Today I will disconnect this and isolate it.

I have to laugh Andrew. https://www.jlwranglerforums.com/forum/threads/has-it-happened.154662/post-3194811

Aren't you afraid that you'll be denied service?

And yes, that's the right cable to remove post 2021 model year https://www.jlwranglerforums.com/forum/threads/ess-battery-cable-change.86624/

 

[Cartman]

you don't have to laugh. the wise laugh last. the key is to put everything back to the condition the car came from before you go to the service center. at least the part you're going to complain about....
Thanks for the second link.

 

[AndySpill]

you don't have to laugh. the wise laugh last. the key is to put everything back to the condition the car came from before you go to the service center. at least the part you're going to complain about....
Thanks for the second link.

....which means, best case, you charge that Aux battery that's been sitting isolated for how long and it actually holds a charge, which you then reconnect prior to a service visit.

Then, if you're lucky, it doesn't cannibalize the main battery in the time of your service visit.

...or more likely, it doesn't hold a charge anymore, in which case you go out and buy a new one, and install it prior to rehooking up the cables.

...or, given that just 1 person reported problems doing the very modification in the thread I linked, that you poo-pooed, and are now doing, you bring your vehicle in for service with the modification and it probably doesn't prevent you from getting service: warranty or fee for service unless it's the battery AND a warranty repair.

@Cartman, I assure you, the laugh is mine. You can't, out of one side of your head talk, as you do above about putting back together at least the part you're going to complain about and say in this link . https://www.jlwranglerforums.com/forum/threads/has-it-happened.154662/post-3194811

"What you expect, you made unauthorised modification, your warranty is 0, especially battery wise... "

Those two thoughts are in contradiction with each other, as according to you all unauthorized modifications would need to be backed out for warranty service of any kind.

The morale of this story: you're now adopting a modification you prior thumbed your nose at.

 

[mbrose1994]

For your consideration, I electrically eliminated my AUX Batt.
My #N3 fuse is now disconnected, nothing can blow it.

See thread: Auxiliary Battery Elimination, post #14 (final post).
The prior posts all contribute excellent information regarding my end result.
Hope this helps.

 

[Cartman]

@AndySpill You're not contradicting anything. I was talking about how it's at least unreasonable to disconnect the AUX battery and go to the service center to claim the battery and complain that they denied your warranty. I never said you shouldn't disconnect the battery. Feel free to disconnect it, but connect it before visiting the service center. It's less work than writing lengthy posts.

 

[AndySpill]

@AndySpill You're not contradicting anything.

Agreed. You are. I'll respect that you English is probably 1000% better than my Slovak and that your words got lost in transation here.

I was talking about how it's at least unreasonable to disconnect the AUX battery and go to the service center to claim the battery and complain that they denied your warranty.

No. https://www.jlwranglerforums.com/forum/threads/has-it-happened.154662/#post-3194811

You said your warranty would be zero with this modification. Not that your warranty would be zero just as it relates to battery issues.

Let me rewrite your sentence above to match your sentiments of this above link.

I was talking about how it's at least unreasonable to disconnect the AUX battery and go to the service center to claim the battery and complain that they denied your warranty.

Understand now?

I never said you shouldn't disconnect the battery. Feel free to disconnect it, but connect it before visiting the service center. It's less work than writing lengthy posts.

Sigh. You just don't get it. Let me try again. Disconnecting that Aux battery is probably going to be the end of its life. Reconnecting it prior to a service visit, it will likely not only fail to hold charge, but given its parallel connection to the main battery, possibly cannibalize that main battery of charge as well, quite possible permanently.

So....your options become either replacing that Aux battery before a service visit, if we follow your plan of putting everything back to factory so all aspects of the warranty will be honored...or

wait for it...

realizing that only 1 poster in that monstrous thread presented a situation were coverage was denied due to a bypassed Aux battery.

Perhaps things are different in non US service both in terms of policy and law, I say void of editorial content.

Let me assure you, replacing that Aux battery will involve a lot more time than reading my posts, whose length often, like here, involves having to explain things to people that first disparage and then adopt modifications.

Please quit while you are not ahead.

 

[Cartman]

sorry I do not have the time to read that, You do not help anybody with anything. Just want to be readed.

 

[AndySpill]

sorry I do not have the time to read that, You do not help anybody with anything. Just want to be readed.

Too bad. You might learn rather than speak from a point of ignorance like you did on my survey thread on bypassing the Aux battery. The very fact that @mbrose1994's post, while cryptic, made no sense to you speaks volume to how if you did read more here you might learn.

In fact it might keep you from offering douchy posts.

 

[Cuyose]

I've read 40 of these threads and still haven't figured out the correct way to isolate the aux.

 

[bobholthaus]

I've read 40 of these threads and still haven't figured out the correct way to isolate the aux.

Simply remove the aux ground wire from the main battery ground terminal (which wire that is varies by year - it’s the thinner wire and my 2023 had an L-shaped piece on it) and wrap it in electrics tape and zip tie it back. Then pull fuse F42. And that’s it.

 

[Cuyose]

Simply remove the aux ground wire from the main battery ground terminal (which wire that is varies by year - it’s the thinner wire and my 2023 had an L-shaped piece on it) and wrap it in electrics tape and zip tie it back. Then pull fuse F42. And that’s it.

Thanks,

Ill try this again but found another thread with the symptoms of dash and infotainment constantly waking up and cycling. Low and behold disconnecting the door C6 connections stopped it!

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