AUX battery delete/bypass - Which method is proper?

[bobholthaus]

Final follow-up to my saga. 2018 JL 2-door Rubicon 2.0 liter. I thought it was the aux batter but it's an E-torque. It turns out it was the radio that was draining the battery. The only option through the dealer was to trade in the $2,100 stock radio with an $850 + labor/testing charges and loss of my map updates plus 2 weeks in the shop waiting for the new radio. Should have done more research and could have done it myself. Who knew you couldn't drive a Rubicon without a radio?

Man, when I read posts like this, I wonder if any of us can own a Wrangler that’s not under some kind of warranty. It’s getting ridiculous to buy, and service, these things.

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[JLfromCA]

E torque adds another level of complexity and cost

 

[bobholthaus]

Looking for quick clarification please:

I’m going to do this today; I don’t want to reread all of the above (due to lack of time). So if I take off Aux negative lead and secure it, and then pull fuse 42, what actually happens? Jeep doesn’t start first try? Then it starts normally? Any error lights on the dash?

I plan to turn off the ESS each time until this arrives, which I am planning on buying today:

https://www.autostopeliminator.com/products/2018-jeep-wrangler-jl-autostop-eliminator

Thoughts? Thanks guys.

 

[Mguy]

Looking for quick clarification please:

I’m going to do this today; I don’t want to reread all of the above (due to lack of time). So if I take off Aux negative lead and secure it, and then pull fuse 42, what actually happens? Jeep doesn’t start first try? Then it starts normally? Any error lights on the dash?

I plan to turn off the ESS each time until this arrives, which I am planning on buying today:

https://www.autostopeliminator.com/products/2018-jeep-wrangler-jl-autostop-eliminator

Thoughts? Thanks guys.

Pulling F42 (do it before isolating the aux battery negative) stops the dual batteries from breaking parallel. It actually prevents error codes, at least most of the time (depending on the state of your software and batteries). Starting and ESS should function normally, both discharging only your main battery. Displayed voltage and charging may be different than before the mod. Good luck.

 

[bobholthaus]

Okay, now what do I do about this (OEM stud being too short to properly use it)? Damn, why does this have to be so complicated? My winch cable fits, but only half the nut fits on. AND, I can’t get my Cascadia solar panel wiring to fit on as well. I did use blue thread locker on there for the moment.

This is what I am referring to (post 2021 JLs):
https://www.jlwranglerforums.com/forum/threads/ess-battery-cable-change.86624/post-1806411

 

[bobholthaus]

I wrapped the end of the aux neg terminal in blue electrical tape (so I can easily reference to my dealer what I touched, when needed), then put flex loom over it, and then zip tied it to the positive wire (the L shaped end actually helps with this zip tying.) Am I missing anything?

Now I just need to figure out a better place to ground my winch (which was grounded by AEV when they did my front bumper, so I doubt there is any slack left on that cable).

AND: I just remembered that I still need to attach my ARB twin to that negative terminal too. Anyone have a link to a cool negative bus bar setup?!

 

[bobholthaus]

Btw, the new OEM battery they put n is hovering at 12.46v. Does that seem like a brand new battery?

 

[bobholthaus]

Okay, my son drove my Jeep this week and I’m just now back in it. I can’t remember if the ESS worked this week after I did the above, but it says “not ready” now. Which means it isn’t working (which is okay, because I plan to buy the override harness anyway). But should I worried about this at all? Fuse 42 is pulled. Aux negative is secure and properly covered. New solar panel on hood. Main battery (OEM) brand new. I am so confused right now.

 

[DubaiMarauder]

The least complex method is to insulate (i.e. cover metal thoroughly with electrical tape) the terminal connectors you remove from both aux battery posts.

It's best to secure the cables against vibration/chafing.

With the aux battery removed, the aux battery ground wire does not have to be disconnected from the main battery negative post.

I wonder if you could use this method to install a fuse block in place of the ESS battery to wire small accessories to that can be controlled via the AUX switches in the dash.

 

[THAW]

I wonder if you could use this method to install a fuse block in place of the ESS battery to wire small accessories to that can be controlled via the AUX switches in the dash.

Clever idea. I might have to try it.

I have a couple of Blue Sea 5024s (https://www.bluesea.com/products/5024/ST_Blade_Battery_Terminal_Mount_Fuse_Block_Kit) in my engine bay. They'd be great for connecting to the ESS/Aux battery terminal connectors.

One thing though: the factory aux switches are already fused.

 

[THAW]

I wrapped the end of the aux neg terminal in blue electrical tape (so I can easily reference to my dealer what I touched, when needed), then put flex loom over it, and then zip tied it to the positive wire (the L shaped end actually helps with this zip tying.) Am I missing anything?

If I understand your configuration correctly, your ESS/Aux battery negative cable is protected from short by the 150A PCR (ESS) fuse, however I'd keep positive and negative cables/terminals as far apart as possible.

 

[bobholthaus]

If I understand your configuration correctly, your ESS/Aux battery negative cable is well insulated and protected from short by the 150A PCR (ESS) fuse, however I'd keep positive and negative cables/terminals as far apart as possible.

Thank you for that reminder.

Can you think of any reason the ESS would now read “not ready “? I just wanted to make sure that there isn’t some other issue going on it’s going to eventually kill my main battery. I have a 2023 diesel. I’m perfectly happy having the system disabled and not having to spend $100 on the auto start stop harness, but obviously the car thinks somethings going on after I did my aux delete. Drove 15 minutes on the highway and it still says not ready. Should I just forget about it and go on?

 

[DubaiMarauder]

Clever idea. I might have to try it.

I have a couple of Blue Sea 5024s (https://www.bluesea.com/products/5024/ST_Blade_Battery_Terminal_Mount_Fuse_Block_Kit) in my engine bay. They'd be great for connecting to the ESS/Aux battery terminal connectors.

One thing though: the factory aux switches are already fused.

My other idea is a big capacitor in place of the ESS battery, as the battery, during ESS events is acting as a quick discharge capacitor anyway. I wonder if that might solve a lot of the weird codes and ESS not ready issues being caused by removing the battery and #42 fuse.

 

[THAW]

Can you think of any reason the ESS would now read “not ready “?

Maybe the new battery wasn't fully charged? Can you put a charger on it?

 

[bobholthaus]

Maybe the new battery wasn't fully charged? Can you put a charger on it?

Well, after a 6 hour drive to Fayetteville, AR, it worked when I got off the highway! So maybe that was it. Was working when I left the dealer after the new batteries. But I hadn’t tried it since I deleted the Aux. but with my new Cascadia 4x4 solar panel on the hood, and sunny all week in St. Louis, I would have thought it would be fully charged. ??‍

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