Is my thinking right here with what my issue is?

[WILDHOBO]

So I replaced my main with a H7. Disconnected the aux negative (labeled 2020 in the picture) and pulled the ess fuse.

Car has no power whatsoever. I'm thinking maybe the IBs? I'm on my way to AutoZone to replace that.

Any ideas????

And I really just recommend that you put everything back to the way it was, and buy a replacement aux 14. You’re going to end up spending more time (time being money) that you’ll save by eliminating the second battery.

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[judojosh]

ASS is auto start stop, if that’s what you’re referring to. Don’t pull the fuse for that.

No, i am referring to the sensor on the negative battery terminal. The battery current sensor. I was under the impression that sensor was called IBS (intelligent battery sensor)

 

[judojosh]

So it looks like the battery sensor is a dealer only part since none of the parts stores carry it.

However, when I came back home I pulled the main fuse array block and tested them for continuity and n2 failed (that is for the ess) so maybe that's the issue?

 

[Maximus Gladius]

So I replaced my main with a H7. Disconnected the aux negative (labeled 2020 in the picture) and pulled the ess fuse.

Car has no power whatsoever. I'm thinking maybe the IBs? I'm on my way to AutoZone to replace that.

Any ideas????

No power can either be wrong ground cable is separated and taped up. Another reason can also be the high amp Z fuse array that’s located on the very outside end (drivers side of fuse box) Are you familiar with this fuse?

 

[Maximus Gladius]

I see we posted at the same time. It’s the Z fuse. Hopefully your dealership will have that one. (Get two)

 

[ShadowsPapa]

So it looks like the battery sensor is a dealer only part since none of the parts stores carry it.

However, when I came back home I pulled the main fuse array block and tested them for continuity and n2 failed (that is for the ess) so maybe that's the issue?

That's not for per se. That's not what it handles. But if that is bad you can have multiple issues. There is no "ESS fuse".

 

[judojosh]

No power can either be wrong ground cable is separated and taped up. Another reason can also be the high amp Z fuse array that’s located on the very outside end (drivers side of fuse box) Are you familiar with this fuse?

that is what I tried first, thinking I taped up the wrong negative terminal. But I swapped them and nothing. I am pretty confident I have the right negative cable to the main battery and the one I have taped up is the aux negative cable.


unfortunately the dealer (both of them) did not have the fuse array in stock. I did order one through autozone as they were the cheapest and fastest turn around. So waiting for that to come in and crossing my fingers thats my fix here

 

[WILDHOBO]

No, i am referring to the sensor on the negative battery terminal. The battery current sensor. I was under the impression that sensor was called IBS (intelligent battery sensor)

It may very well be called that. If absolutely keep that sensor. It’s needed for the smart alternator.

 

[Lost1wing]

So it looks like the battery sensor is a dealer only part since none of the parts stores carry it.

However, when I came back home I pulled the main fuse array block and tested them for continuity and n2 failed (that is for the ess) so maybe that's the issue?

How did you test the fuse array? Did you pull it out? N2 is pretty much a bus bar that powers part of the power center. Now n3 150 amp could be what you are talking about.

The ibs is not your not power issue.

Maybe I just need a little refresher course and I'm wrong.

 

[djthumper]

that is what I tried first, thinking I taped up the wrong negative terminal. But I swapped them and nothing. I am pretty confident I have the right negative cable to the main battery and the one I have taped up is the aux negative cable.


unfortunately the dealer (both of them) did not have the fuse array in stock. I did order one through autozone as they were the cheapest and fastest turn around. So waiting for that to come in and crossing my fingers thats my fix here

Even quicker and cheaper than Amazon?

 

[ShadowsPapa]

So it looks like the battery sensor is a dealer only part since none of the parts stores carry it.

However, when I came back home I pulled the main fuse array block and tested them for continuity and n2 failed (that is for the ess) so maybe that's the issue?

OK, N2 isn't a fuse. It's direct from the high current fuse array "bus" to the crank/main battery positive.

N3 goes to the aux battery.

There is no "ESS" fuse although the fuse key on the PDC lid calls N3 exactly that. But it doesn't really handle "ESS" as such. It's a direct line from the alternator output to the aux battery positive.
Oddly, even though the auxiliary battery is connected to the main battery positive through the PCR, it doesn't charge when N3 is blown. So it's more for keeping the aux battery up and of course if it fails, then ESS won't function correctly, and many other things likely won't as well.

N3 goes to the auxiliary battery positive THROUGH the PCR (a heavy-duty relay between N3 and the aux battery positive)

IBS is Intelligent Battery Sensor and yes, it's likely a dealer item.

 

[mtudb24]

So it looks like the battery sensor is a dealer only part since none of the parts stores carry it.

However, when I came back home I pulled the main fuse array block and tested them for continuity and n2 failed (that is for the ess) so maybe that's the issue?

you can get the IBS sensor on Amazon. I verified this part with @ShadowsPapa number and its correct

https://www.amazon.com/dp/B0CCQM3G5J?ref=ppx_yo2ov_dt_b_fed_asin_title

You can also get the Z fuse on Amazon. Mine is correct for 2021 max tow truck. Not sure if your application is the same, but they have many versions.
https://www.amazon.com/dp/B0D9BPMV2V?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

 

[ShadowsPapa]

you can get the IBS sensor on Amazon. I verified this part with @ShadowsPapa number and its correct

I forgot about that - yeah, Amazon, often Jeep parts sellers working through Amazon.

 

[judojosh]

it was the fuse block. replaced and it started right up

 

[Schaft]

My opinion and my opinion only, it seems there is a fault in the architecture of this vehicle.

If we have to put a battery tender / charger on a $50K+ vehicle if it sets a few days a week without being used or driven less then a hour a day, that seems wrong.

My mom has a 4 year old equinox with start stop. 18K miles later and still running original batteries. So you can do the math on how long that thing sets between uses. Sister has a 2016 Malibu with aux battery in the trunk, she had to replace her aux and main battery in 2022 and now has 54,000 miles. That's 6 years and very few miles for the years. It sat way more then a couple days a week and they've never had to trickle charge their system to keep it operational.

Our family's modern farm Tractors / Harvesters / Sprayers which can cost all have J1939 Can Bus, and going to CAN FD, and the ethernet systems. We have as many modules as the Jeep does if not more on many Harvesters, and we don't see battery failures as much as these Jeeps do. And they set for much longer then days / weeks in-between uses, and we don't always run trickle charger on them.

Not trying to be disrespectful or argumentative , but I think there is a flaw on how Jeep approached this system.

After having both batteries replaced while still under warranty, I asked the Service Department attendant what the problem was, with the gladiator charging system, etc. He was nice enough to be honest and tell me that the auxiliary battery was way under engineered. As much as I believe that, in my case, it was due to the short drives/parasitic draw. And not being allowed to be fully recharged. So like many others, I have resorted to a battery tender. I haven’t had a problem since I have been using it. Also, don’t use the Jeep for short trips anymore. This only works if you have a second vehicle.

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