3.6L ESS Aux Battery Bypass

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Jebiruph

Jebiruph

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If you permanently disable ESS, can you get rid of the Aux battery?
Can you leave the bypass mentioned here in place and get rid of the Aux battery?
Sorry if it is a dumb question.
First answer is probably not, but haven't tried. Second answer is maybe, but haven't tried. I've only started with the Aux battery bypassed, which is the problem I was trying to solve.



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Torero

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First answer is probably not, but haven't tried. Second answer is maybe, but haven't tried. I've only started with the Aux battery bypassed, which is the problem I was trying to solve.
My simple reasoning is that if you can bypass the aux then you make the system believe is there even if it isn’t.
Since I installed a supercharger my ESS has been disabled. I don’t know how they did it.
 
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My simple reasoning is that if you can bypass the aux then you make the system believe is there even if it isn’t.
Since I installed a supercharger my ESS has been disabled. I don’t know how they did it.
I agree with what you are saying, but there is some unexpected behavior related the Aux battery that I can't explain, so it needs tested. I actually think the system doesn't know the Aux is bypassed, I didn't get any errors during my brief experiment.
 
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After thinking about remote area travel reliability, I realized that the bypass could also be used to bypass any blown high capacity fuse. Due to the high current rating of some of those fuses, a higher current bypass might be needed. After looking at the fuse holder in the first bypass, I simplified the design even further to accommodate for the use of higher current components.
bypass kit 3.jpg

The new bypass just uses spade lugs to connect to the fuse contacts. This one uses 10 GA compared to the 12 GA of the original and is only rated for 40 amps due to the manufacturers rating of the terminals, but with the right terminals and wire you could get to a higher current rating. I found blade fuses rated up to 100 amps on amazon.
 
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Jebiruph

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This one uses 10 GA compared to the 12 GA of the original and is only rated for 40 amps due to the manufacturers rating of the terminals, but with the right terminals and wire you could get to a higher current rating.
Thought about this a bit more. It seems to become exponentially more difficult to deal with higher current components due to the thickness of wire required. Then I realized you get the same result from multiple smaller gauge wires. Based on this chart that came with my 10 GA wire, 2 10 GA jumpers gets you to 100 amps. It may not look as good as a single jumper, but 2 or 3 in parallel could get the job done.

wire chart.jpg
 

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Does anyone have the factory wiring diagram for the PDC and the batteries?
 
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I've seen quite a few posts related to failed Aux batteries causing flaky or dead electronics, stalling and failing to start/auto restart. I've come up with a simple way to temporarily bypass a bad Aux battery (also blown PCR fuse or bad PCR) and get back on the road. Warning - this post contains a lot of informed assumptions, so post your related experiences to help validate or invalidate any information I've provided.....
@Jebiruph , Jerry: have you been able to come up with a way to permanently install this fused wire (maybe permanent install was never part of your design) between N1 and N2, and still be able to get the Power Distribution Center's (PDC) plastic cover back on?

Need I tell you, the connectors to these high order fuses are upside down "L" shapes with their screw down nut undetachable from the "L" assembly. This makes putting your fused lead under this "L" assembly near impossible given the proximity of all of the high order fuses connections, except in a way that seems to prevent the PDC cover from being reinstalled.

Maybe "the play" is to have this device on hand and only pair up N1 and N2 in times of such need, or maybe attach the leads above the upside down "L" connectors with another properly sized nut. Even then, since I thought it only appropriate to use thick (low gauge) wire, I'm finding it hard to make this installation permanent AND get the PDC's cover back on.

I gleaned this a permanent install on your part from the normal detachment of its fuse.

Thanks.
 
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@Jebiruph , Jerry: have you been able to come up with a way to permanently install this fused wire (maybe permanent install was never part of your design) between N1 and N2, and still be able to get the Power Distribution Center's (PDC) plastic cover back on?

Need I tell you, the connectors to these high order fuses are upside down "L" shapes with their screw down nut undetachable from the "L" assembly. This makes putting your fused lead under this "L" assembly near impossible given the proximity of all of the high order fuses connections, except in a way that seems to prevent the PDC cover from being reinstalled.

Maybe "the play" is to have this device on hand and only pair up N1 and N2 in times of such need, or maybe attach the leads above the upside down "L" connectors with another properly sized nut. Even then, since I thought it only appropriate to use thick (low gauge) wire, I'm finding it hard to make this installation permanent AND get the PDC's cover back on.

I gleaned this a permanent install on your part from the normal detachment of its fuse.

Thanks.
I never tried to get the cover on with jumper installed. My test was with 12GA wire held on with regular nuts and I didn't perceive any clearence issues. The wing nuts were an after thought for emergency installation. What GA wire are you using?
 

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I never tried to get the cover on with jumper installed. My test was with 12GA wire held on with regular nuts and I didn't perceive any clearence issues. The wing nuts were an after thought for emergency installation. What GA wire are you using?
6 gauge…. ;) I play things safe, maybe too safe here and as a result lacking in bendability. I still think it might be hard to get the PDC cover back on even with larger gauge (i.e. smaller diameter) wire, but appreciate you replying and letting me know that the things I'm experiencing are not out of the norm.

I'm content to use this invention of yours, otherwise stored in my cargo tub, as needed, which is hopefully never. And I appreciate you doing the research and making it available to people like me. I thought enough of your idea to try to implement it: imitation being the best form of flattery.

Thanks for your response.
 

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I for one think @Jebiruph has done excellent research and testing of his homemade emergency bypass kit and having this bypass kit would be great to allow one to at least get to somewhere where the battery issues could be addressed, my son made the comment once to me when we saw. Jeep broke down on the side of the road that it was a terrible place to break down to which I responded anyplace is a terrible place to break down
 
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So after a couple months of my voltage reading consistently 14.7 -14.8v, I decided to put the bypass to the test and see if running with the aux battery bypassed would change the running voltage any. 3 days in and it's running 14.4 - 14.5v, not sure if it's making any difference or not. The jumper is attached to N1 and N2 with wing nuts and aux ground is disconnected, PDC cover fits over jumper. I replaced the aux ground cable nut with a wing nut, so if I suspect a problem with the jumper, I can quickly reattach the aux ground cable and pull the jumper fuse to return to normal.

bypassed.jpg
 

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@Jebiruph are you gettig any messages displayed in the EVIC telling you that you have a problem with ESS or any other weird messages ?

From my understanding the voltage is not supposed to run 14+ all the time as it may indicate a battery going bad or did you disconnect the IBS relay so it constantly has the alternator charging
 

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You know.. I had a thought about this, this morning...

Why not just disconnect the aux - lead, and unplug the control wire harness from the aux battery relay (forget the name). If it works the way that we think it does, then posts 1 & 3 will stay jumpered because the relay will never be energized... and it looks factory!
 

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I think many are underestimating the technology behind the ESS and the-Aux battery. There is I believe another factor at play here where the Aux battery is essential. That is the Managed Charge System where the Alternator does not load the drivetrain when not needed. I believe the Aux battery serves some vital ECM management components to ensure consistent voltage and behavior.

Any FCA electrical engineers on the forum?
 

                           
























































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