3.6L ESS Aux Battery Bypass

OldBlue

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Lots of great info here from a LOT of very smart people. I read through the first few pages and last 6 or so, and I have to admit my eyes started to gloss over, as I tried to follow all the info but got lost. 😳 Wondering if anyone tried this bypass with the 2.0L? Both my Jeeps ('20 JLU and '19 WK2) use the auxiliary battery and I'd love to bypass it in both of them. I still need to do more research on the WK2 forum to see if it's possible on that one.
 

StaindReality

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You only need the jumper if you don't have the software update and can't start without it. If you have the software update, the jumper just keeps the ESS test from failing and turning on the error light. I wouldn't bother taping up the cable either, just bend it out of the way.
So to verify. I have a 19 sport. I do not need the jumper? I just have to disconnect the negative aux from the main battery to stop using the aux battery all together when I replace my main battery?
 

Rhinebeck01

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Will tazer take warning light off?
@StaindReality

So, you would have no issue with..... with the EVIC light coming on .... being there all the time on your 2019 JL ? You would see the JL start on the second try .. have the error light.

You will want the jumper!!

Just easily install the $8.00+- fused, N1-N2 bypass jumper and you will have none of that. JL will start on first attempt and no error light thrown/turned on. Yes, you also have to have the Aux negative wire disconnected from the Main battery Neg. terminal.

.
 

jeepdabest

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So to verify. I have a 19 sport. I do not need the jumper? I just have to disconnect the negative aux from the main battery to stop using the aux battery all together when I replace my main battery?
Without jumper you will have a yellow warning light on dash
 

StaindReality

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Ok. Thank you for quick response. I got 10 ga. 40 amp inline fuse coming. I’ll go ahead and replace old main battery with new battery now and use the jumper Thursday when jumper arrives

One more question. When hooking up the jumper. Is it required to unhook main battery at all? Or just hook up jumper. Then unhook aux. negative.
 

Rhinebeck01

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Ok. Thank you for quick response. I got 10 ga. 40 amp inline fuse coming. I’ll go ahead and replace old main battery with new battery now and use the jumper Thursday when jumper arrives

One more question. When hooking up the jumper. Is it required to unhook main battery at all? Or just hook up jumper. Then unhook aux. negative.
@StaindReality

You'll need Wing Nuts (see pic for size) to secure the N1-N2 fused bypass jumper.

No need to "unhook Main battery".

Do not use/ loosen the nuts that are securing N1 and N2. Place one ring connector on N1 and secure with a Wing nut. Do the same with the other ring connector and a wing nut in regard to N2.

Just have the 40 amp fuse out of the fused bypass fuse holder ..... and secure the 2 ring connectors and then insert the 40 amp fuse.

Remember to disconnect the Aux Neg. wire that is connected on the Neg terminal of the Main battery.

Do all mentioned and you will be set-up to run with just the Main battery.

Remember, when running with just the Main battery ....to not use of limit use of ESS. Press the ESS button or buy and adjunct that does that for you .... like a SmartStopStart unit.


jumper.jpeg
 

Rhinebeck01

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@StaindReality

You will be disconnecting #6 in the picture below. That is the Aux battery Negative on the Main battery Neg terminal..

Disconnect it and cover the end with something non-conductive.

Leave a Wing Nut on the terminal that you took the nut off to disconnect the cable.

This way if you want to reconnect for any reason, you can do with no tools, thanks to the Wing nut.

battery numbered.jpg
 

StaindReality

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You all are great. Thank you so much for quick response and helping get this straight.
 

Rhinebeck01

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