VIDEO : HOW TO Replace the Main & Auxiliary Battery on a JL Wrangler / JT Gladiator

wayoflife

Administrator
Staff member
VIDEO : HOW TO Replace the Main & Auxiliary Battery on a JL Wrangler / JT Gladiator

Having your Jeep battery die really isn’t that big of a deal, especially if you have a set of jumper cables handy and another vehicle near by that's willing to help out. But, what do you do if you're out in the middle of nowhere and all alone? That just happened to Cindy and I and if you can believe it, on our Jeep JL Wrangler that's only about two years old! Fortunately, we did have our super compact, Type S Jump Starter with us and that was able to get us going again. However, once we got home, we discovered that our battery still wasn't holding a charge or at least, not enough to fire up the engine. All the lights worked, the radio played, windows opened and closed and even the dash lit up just fine - there just wasn't enough juice to get it to get it to crank.

Well, as some of you may or may not know, the Jeep JL Wrangler and JT Gladiator Truck has two batteries under the hood - a large traditional size battery that's used for cranking the engine and a smaller auxiliary one that powers everything else, including a relay that connects the two batteries together for cranking. Needless to say, even if your main battery wasn't dead, you could still have problems starting your engine if your auxiliary battery is dead or dying. I should note that we were actually seeing strange messages on the dash EVIC including one for, Aux Switches being temporarily disabled due to "Battery Charging" and another saying, "Service Shifter". So, when it comes time to replace one, you're more than likely going to need to replace both and for us, we decided to use the opportunity to upgrade our main battery to an Odyssey. I wish we could have upgraded our auxiliary one too but there really isn't a whole lot to choose from and so I just got a Super Start Platinum from my local O'Reilly Auto Parts Store. In this video, you'll get to see just how easy it is to replace the main battery AND what all you'll need to do to replace the auxiliary one. We hope it helps you out.


Type S Jump Starter: https://amzn.to/31fyFRI
Odyssey Battery 48-720: https://amzn.to/3eB8FmU
Milwaukee Cordless Ratchet: https://amzn.to/3fLGao3
Tekton Torx/E-Sockets: https://amzn.to/3jpCvhB

#wayalife #odysseybattery #oreilly #milwaukee #tekton
 

wayoflife

Administrator
Staff member
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Ddays

Hooked
Wow, nice convenient location for the aux battery :rolleyes2: Thanks for the video. :thumb:
Bonus footage was the best.
 

wjtstudios

Hooked
Could they have buried that Aux battery any deeper into the engine bay?? It gave me bad memories of the good old oil cooler on the 3.6... crazy, but great info for someone having issues like you were having.

Ripley’s still full pup!

Great video as always!


2015 JKUR AEV JK350
1985 CJ8 Scrambler
 

CalSgt

Hooked
Great "how to," I'm glad I watched, I thought the Auxiliary battery was in a totally different spot.

What exactly does the auxiliary battery do?
 

WJCO

Meme King
What a pain in the ass. Thanks for the detailed video. I hope I don't have to deal with this anytime soon. I carry a jump starter just like that one in the beginning of the video just in case.
 

cozdude

Guy with a Red 2-Door
Glad you posted this. Had no idea the new Jeeps had aux batteries. Seems odd they would add a second one in where a main battery could have handled it.
 

wayoflife

Administrator
Staff member
Wow, nice convenient location for the aux battery :rolleyes2: Thanks for the video. :thumb:
Bonus footage was the best.

LOL!! I know, right? I always knew where it was but didn't realize it was gonna be that much of a pain to get to. Being that it goes out so quickly, you'd think that someone would have put it somewhere a bit easier to get to.

Could they have buried that Aux battery any deeper into the engine bay?? It gave me bad memories of the good old oil cooler on the 3.6... crazy, but great info for someone having issues like you were having.

Ripley’s still full pup!

Great video as always!

LOL - geeze, no kidding! I hated that oil cooler but I think that was harder to get to.

Great "how to," I'm glad I watched, I thought the Auxiliary battery was in a totally different spot.

What exactly does the auxiliary battery do?

The main battery is for cranking the engine. With the auto start stop feature, it needs to be bigger to handle the load. The auxiliary battery provides power to just about everything else.
 

wayoflife

Administrator
Staff member
What a pain in the ass. Thanks for the detailed video. I hope I don't have to deal with this anytime soon. I carry a jump starter just like that one in the beginning of the video just in case.

That jump starter is a god send. It really is a wonder to me that more people don't have one especially being that they're so cheap and so useful.

Yeah that's a pain in the ass. And I have a 3rd battery on my jeep

As in, you have a dual battery setup? Good god, what a pain replacing the auxiliary battery will be.

Glad you posted this. Had no idea the new Jeeps had aux batteries. Seems odd they would add a second one in where a main battery could have handled it.

The main battery is just for cranking the engine. A better solution would be to just get rid of the stupid auto start stop system but of course, the gov requires it. :naw:
 

lefty02

Member
Wow!!! I’m sure that looked good on paper to whatever engineer at Chrysler designed it. Those guys don’t usually get there hands dirty so they have no idea what a pain in the ass they created.
 

Dale72

Hooked
That jump starter is a god send. It really is a wonder to me that more people don't have one especially being that they're so cheap and so useful.



As in, you have a dual battery setup? Good god, what a pain replacing the auxiliary battery will be.



The main battery is just for cranking the engine. A better solution would be to just get rid of the stupid auto start stop system but of course, the gov requires it. :naw:
No mine has the 2.0 4 cylinder engine which has a battery right in front of the rear axle

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Andy5160

Hooked
Awesome Gideon ant it provides tons of help.
Thanks as always [emoji106][emoji106][emoji106][emoji106]


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highoctane

Caught the Bug
Man what a pain in the ass. I think my JT will be needing this sooner than later. My ESS never works. If I scroll through the dash cluster to the page that shows ESS status it has a message saying battery voltage to low. It hasn’t lit any warning lights or thrown any error messages yet though.


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wayoflife

Administrator
Staff member
Can’t edit my response meant to say
“Awesome video “

LOL - Glad we could be of help with this :)

Man what a pain in the ass. I think my JT will be needing this sooner than later. My ESS never works. If I scroll through the dash cluster to the page tray shows ESS stays it has a message saying battery voltage to low. It hasn’t lit any warning lights or thrown any error messages yet though.

So, if it gets too low, you'll start to see problems show up on the EVIC. Not being able to shift the automatic transmission is one of them.
 

OverlanderJK

Resident Smartass
That jump starter is a god send. It really is a wonder to me that more people don't have one especially being that they're so cheap and so useful.



As in, you have a dual battery setup? Good god, what a pain replacing the auxiliary battery will be.



The main battery is just for cranking the engine. A better solution would be to just get rid of the stupid auto start stop system but of course, the gov requires it. :naw:

Doesn’t the turbo have three batteries? One under the jeep somewhere too?


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