Rhinebeck01

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Yes , you can get at the Aux battery, from above but..... A lot more to the exchange, going from up above though.. A lot more to screw up, too.

The Factory Service Manual has you fooling with the fender liner.... yuk...

Anyway, when I watched my tech friend changing out the Aux battery on a JL, he mentioned to me, that he would rather just pull the whole fender flare, versus fooling with the fender liner in order to get to the Aux battery... He told me it would be so much easier/faster..

Oh, prior to ever pulling a JL fender flare, you might just want to purchase a couple of fender flare clips, just in case you break one.

You can get them here for less than a dollar each. https://www.quadratec.com/p/omix/fender-flare-clip-wrangler-jl-gladiator-jt-11609.41

So, I remembered seeing this video a year or so ago and geeez, my tech friend had the right idea, in regard to just easily pulling the flair to gain easy access to the Aux battery.

Here is the video... it is worth the time to watch it, in it's entirety.. ESPECIALLY, if someday you yourself might want to replace your Aux battery yourself.






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Dkretden

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This is very good. I learned something. Thank you.

this is the same YouTube dude who had the original video out to go through the fuse box.

this seems a whole lot easier with less chance of damaging anything. And the clips for a buck a piece is great to see as well.
 

Htfan

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This is great info! I didn't realize that you could get at the aux/ess battery that way. However, it seems stocking up on plastic clips is the way to go. I imagine clip breakage is probable.
 

ErAcEr

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For those that are interested, here is a pic of the Aux battery and the part # of the Aux battery.

Aux Battery - JL.jpg
How do I know if my aux battery is bad? Im sure its in another post somewhere but lazy to go searching.
 
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Rhinebeck01

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OEM Aux battery. It's Mopar part # is 56029759AB

For an aftermarket Aux battery for your JL, ask the parts guy for an
Group Size 400, "AUX14" battery.

Here are 2 , Aux battery aftermarket replacements:

DieHard Platinum AGM Battery, BCI Group Size 400, 200 CCA
Part # AUX14-1

Super Start Platinum Auxiliary Battery Group Size 400
Part #AUX14
 
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Rhinebeck01

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Here is a snip from the Factory Service Manual.. Note, that the service manual says to first, Disconnect and Isolate the negative battery cable(s) . IMPORTANT --They are referring to the negative battery cables up top / in the engine compartment, on the Main battery!

After doing that, you remove the 3 bolts from the supplemental battery tray (Aux's battery tray) and lower the Aux battery down a bit.... just enough so that you can get to and disconnect the pos and neg cables (then isolate them) from the Aux battery. After both the cables are disconnected, your Aux battery is free to drop down and to be replaced.

aux-replace.jpg
 
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Rhinebeck01

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For those that are interested, here is a pic of the OEM Aux battery and the part # of the Aux battery.

For an aftermarket Aux battery for your JL, ask the parts guy for an
Group Size 400, "AUX14" battery.

Aux Battery - JL.jpg
 
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EU_Wrangler

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Here is a snip from the Factory Service Manual.. Note, that the service manual says to first, Disconnect and Isolate the negative battery cable(s) . IMPORTANT --They are referring to the negative battery cables up top / in the engine compartment, on the Main battery!

After doing that, you remove the 3 bolts from the supplemental battery tray (Aux's battery tray) and lower the Aux battery down a bit.... just enough so that you can get to and disconnect the pos and neg cables (then isolate them) from the Aux battery. After both the cables are disconnected, your Aux battery is free to drop down and to be replaced.

aux-replace.jpg
Is the Factory Service Manual available to download? I can't find any thread in the forum related to the manual
 
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Rhinebeck01

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Is the Factory Service Manual available to download? I can't find any thread in the forum related to the manual
@EU_Wrangler


Sure, if you want, you can buy the Factory Service Manual....

Get it here or do a Google search and find it/buy it elsewhere:

For 2018 SM:
https://www.factoryrepairmanuals.co...tory-service-manual-usb-original-shop-repair/

For 2019 SM:
https://www.factoryrepairmanuals.co...Omas4X0mHDbcR1GlHFXKyGgzxSrPMrKhoCGtUQAvD_BwE

For 2020 SM:
https://www.factoryrepairmanuals.co...Omas4X0mHDbcR1GlHFXKyGgzxSrPMrKhoCGtUQAvD_BwE

Past forum thread talking SM:
https://www.jlwranglerforums.com/forum/threads/2018-wrangler-jl-factory-service-manual.2637/
 

Rubi

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Yes , you can get at the Aux battery, from above but..... A lot more to the exchange, going from up above though.. A lot more to screw up, too.

The Factory Service Manual has you fooling with the fender liner.... yuk...

Anyway, when I watched my tech friend changing out the Aux battery on a JL, he mentioned to me, that he would rather just pull the whole fender flare, versus fooling with the fender liner in order to get to the Aux battery... He told me it would be so much easier/faster..

Oh, prior to ever pulling a JL fender flare, you might just want to purchase a couple of fender flare clips, just in case you break one.

You can get them here for less than a dollar each. https://www.quadratec.com/p/omix/fender-flare-clip-wrangler-jl-gladiator-jt-11609.41

So, I remembered seeing this video a year or so ago and geeez, my tech friend had the right idea, in regard to just easily pulling the flair to gain easy access to the Aux battery.

Here is the video... it is worth the time to watch it, in it's entirety.. ESPECIALLY, if someday you yourself might want to replace your Aux battery yourself.

Excellent write-up, thanks.
 
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Rhinebeck01

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For those that are interested, here is a pic of the Aux battery and the part # of the Aux battery.

Aux Battery - JL.jpg
Thanks for posting these!

It says the max charging voltage is 14.4 but I remember seeing mine at 14.5 or maybe 14.7 at times.

Also, to effectively bypass this but not to over tax the alternator, can't we replace it with a sufficient capacitor?
 

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