Aux Bypass Didn't Clear Screen

[Readyt]

2020 Gladiator and have been running the Tazer Mini for years with the Auto Start Stop button set to off. Regardless I still have had to replace the Aux battery twice, , once under warrenty. The Jeep is on a battery tender whenever its going to sit in the garage for more than a couple of days to extend the battery life.

68,000 miles on the truck and I got the dreaded Start Stop warning a couple of days ago so I decided to do the bypass.
-Pulled the #42 Fuse,
-disconnected the thinner ground wire,
-heat shrunk the end and zipp tied it away.
-Went in and cleared all codes with the Tazer,
Started the truck and the codes and errior light came back, went through the process again, and they came back again. Now the battery tender says "Unable to charge, Bad Battery"
Any idea of what am I doing wrong?

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[sharpsicle]

What's the state of your main battery? The aux could have been carrying the main, and now that it's gone the system is worse.

What codes is it giving you? The existence of codes means nothing unless we know what they are.

This could be a different issue, it could be an IBS issue, or it could be something that just needs time. Hard to know at this point.

 

[Labswine]

I just had BOTH batteries replaced in my Overland. The main was reading 11.4 volts with nothing on. I too had the dreaded service the AS/S system message.

My batteries simply aged out. They were the factory originals...ordered 5/19, delivered 7/19, so they were at least 7 years old, and I have around 46,5xx miles on it (the joys of retirement).

I thought about doing the aux battery delete as you described but, I also thought long and hard about it in that all the systems in our vehicles are so intertwined that if you messed with one then three (or more) other things would start to go wonky. Basically, when technology goes 'boink'.

I asked the stealership where I bought her from how much to do the task, and they said between $750 and $800 to do it, and the batteries they used were warranted for 3 years.

I went to my trusted independent mechanic (been using them for well over a decade, even my Dad used them for at least a decade more) and they told me it'd be right around $600. They also use 3 year warranty batteries. They replaced the main with an AGM battery and, I don't know what they used for the aux. Only took them like 45 minutes to do the whole job. Codes cleared and no stoopid AS/S idiot light sitting above my fuel gauge.

The only odd thing I noticed is that some of the icons on my info system, I have the 8.4" nav system, look different than before. Dunno why but, everything still works just as good as before. New battery shows 12.7 volts with nothing turned on.

I'd simply replace your aux battery as well and just continue doing what you did before.

 

[Lunentucker]

If you haven't replaced the main battery that could be the issue, especially after it spent much of its life trying to recharge the Aux battery while that was still connected in parallel to it.
I'd get a good test on the main battery and go from there.

 

[Lost1wing]

What is the battery voltage? Double check ALL connections. If you had the Aux replaced from the top you need to check all those connections too. Anything the dealer touched and what you touched.

If you can start the truck, I can't see why your charger cannot charge the battery. Perhaps your charger is bad? Or is it detecting a bad battery?

 

[Readyt]

What is the battery voltage? Double check ALL connections. If you had the Aux replaced from the top you need to check all those connections too. Anything the dealer touched and what you touched.

If you can start the truck, I can't see why your charger cannot charge the battery. Perhaps your charger is bad? Or is it detecting a bad battery?

Voltage is 12.1, Charger is saying Bad Battery

 

[Bandit’s Lair]

Looks like it’s time for a new main battery. If you want to go cheap look for an Interstate Battery shop and ask if they have a “Blem” in the correct size. I threw down the Benjis for an Odyssey 94R and have been very happy with it. That’s pretty much both sides of the cost spectrum unless you go Lithium.

 

[sharpsicle]

Voltage is 12.1, Charger is saying Bad Battery

OK yeah, this is what happens when you read too much on the internet with everyone going "aUx BaD, sOuRcE oF aLl PrObLeMs".

Your aux wasn't bad, it was your main!

 

[Lost1wing]

Looks like it’s time for a new main battery. If you want to go cheap look for an Interstate Battery shop and ask if they have a “Blem” in the correct size. I threw down the Benjis for an Odyssey 94R and have been very happy with it. That’s pretty much both sides of the cost spectrum unless you go Lithium.

When I need a battery, I generally go with inteestate. Never purchased a blem. Is that just a return that tested good?

 

[Lost1wing]

Voltage is 12.1, Charger is saying Bad Battery

I would put that charger on a different battery to verify that you don't get a bad battery message on that one. Some chargers will not charge if they detect a bad cell. 12.1vdc does not sound like a bad cell. Just a very weak AGM. If you are trying to charge it still installed, it could be possible your charger cannot keep up with the drain. What charger are you using? Can you verify all accessories/ lights are off?

It might be better off to just remove the main, have it charged and load tested. Or just skip that part and get a new main, charge it and then install.

 

[Readyt]

Went into the Tazer, Removed and cleared all codes, (Only thing showing was the Stop start) then did a full reboot of the Tazer and Whalla, the notifacation went away. Just plugged the charger back in , so I will see what it says in an hour or so.

Still going to replace the Main, probably with a Odyssey because they are at Auto Zone. When I was in MOAB two years ago and my Aux failed and was under Jeep warranty, I couldn't get it replaced because there was no Jeep Dealer within 100 miles, had to buy one. For the future I want something I can warranty anywhere and there are Auto Zones everywhere.

 

[Readyt]

OK yeah, this is what happens when you read too much on the internet with everyone going "aUx BaD, sOuRcE oF aLl PrObLeMs".

Your aux wasn't bad, it was your main!

When I ocasionally checked the start stop by turning it back on it wouldn't be charged even after hours of driving with the system off. Been a PITA since its been in there (3rd one). So yep, it was on the way out for a while.

 

[Bandit’s Lair]

When I need a battery, I generally go with inteestate. Never purchased a blem. Is that just a return that tested good?

Legends goes: These started out with a batch of batteries made for Costco or Sam’s that were mislabeled. Mind you this was a massive order because they deal in bulk. The store chain refused the order and Interstate was stuck with a butt ton of batteries that were incorrectly labeled but brand new. They started selling them at deep discounts and they sold like hotcakes. Ever since then I’ve always been able to find a blem at deep discounts so not sure how they’re still around but I don’t complain. Example is I once bought a Group 78 Interstate for a truck for $109. December ‘25 I bought a Blem for a Chrysler Pacifica 4.0l for $86. Both were brand new batteries. Not a scratch on the posts.

 

[sharpsicle]

When I ocasionally checked the start stop by turning it back on it wouldn't be charged even after hours of driving with the system off. Been a PITA since its been in there (3rd one). So yep, it was on the way out for a while.

uhh, that’s not testing the aux though. The aux is always connected to the main in that scenario. You’ve been seeing signs that the main was failing but were ignoring them.

But okay, point is you found the issue and can now address it.

 

[Red Mojave]

ReadyT, you mentioned you, ”disconnected the thinner ground wire.”
This is going to sound a bit off, but I had a 2020 Jeep like you.
The thinner ground wire on that year was the MAIN ground wire on my Jeep. The thicker ground wire was the aux battery ground wire on my 2020 Jeep. Later years Jeep switch the large cable to the main battery post (like it should be), and the smaller cable to the aux battery.
A Intelligent Battery Sensor (IBS) is also mounted under the battery cable between the ground cable and battery post. That can go bad sometimes.
I am just throwing some ideas out on the table.
Good luck

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