Aux Battery Bypass

Ikentrouble

New member
I have a question which of course leads to other questions . I replaced my main battery a year ago in August, I replaced my aux battery in February. Everything worked fine for a few months then the messages started up again. Fast forward to this past weekend. I was on my way to do some wheeling when the Jeep just quit and did not want to start, no click just a lit up dash. I grabbed my jump pack and managed to start the Jeep, but I had no power steering. I managed to get into a parking lot before it died again. In a parking lot I did the aux delete, I disconnected the negative cable from the aux battery, I put a jumper with a 40amp fuse between N1 and N2. Made it home safe and sound. First question the start and stop function would sometimes work sometimes not, sometimes I get messages about charging, sometimes not. So where is the problem? Next question, I have blown that 40amp fuse twice, if I had a short somewhere I could understand blowing the fuse while driving over Chicago potholes or different railroads tracks near me, but the two times it has blown I was driving maybe 2 miles an hour over flat ground. Any ideas??
 

wayoflife

Administrator
Staff member
What's blowing your fuse is startup. You do NOT want to bypass the auxiliary battery as it exists to PROTECT your Jeep's computer from startups - you know, the think that's been blowning your fuses.
 

Ikentrouble

New member
What's blowing your fuse is startup. You do NOT want to bypass the auxiliary battery as it exists to PROTECT your Jeep's computer from startups - you know, the think that's been blowning your fuses.
It's not blowing at start up, I have the start stop turned off.
 

Jeeptime

Active Member
Jeep will replace my aux battery under warranty. I understand they will replace with stock Mopar battery.
Am I better off replacing the aux battery with a upgraded quality battery? Does anyone recommend the best battery to replace the aux battery?
I do hate the stop start feature. I turn it off and never use it. I do want to keep the system stock.
Thanks
 
Jeep will replace my aux battery under warranty. I understand they will replace with stock Mopar battery.
Am I better off replacing the aux battery with a upgraded quality battery? Does anyone recommend the best battery to replace the aux battery?
I do hate the stop start feature. I turn it off and never use it. I do want to keep the system stock.
Thanks
While under warranty, it should be obvious to use the Mopar battery. After that it is a matter of opinion. A longer warranty seems ideal, but only if the supplier can back it up with a quick replacement. I would tend to choose the most available supplier/brand.
 

Boston Bill

New member
There is a very inexpensive way to get rid of the aux battery system.
And the expensive way.
 

wayoflife

Administrator
Staff member
There is a very inexpensive way to get rid of the aux battery system.
And the expensive way.
Again, you DO NOT want to get rid of the auxiliary battery. It exists to help protect your Jeep's computer from the surge it gets from starting your engine. Removing it WILL cause damage to the computer over time. This isn't my opinion, this is straight from the engineers at Jeep.
 

Boston Bill

New member
Again, you DO NOT want to get rid of the auxiliary battery. It exists to help protect your Jeep's computer from the surge it gets from starting your engine. Removing it WILL cause damage to the computer over time. This isn't my opinion, this is straight from the engineers at Jeep.
Didn’t know that. Thank you. I guess when the time comes I will use AGM batteries.
 

jeeeep

Hooked
It's not blowing at start up, I have the start stop turned off.
you have the start/stop disabled, but it is not turned off.

Jumping N2-N3 is bypassing a portion of the Z case fuse array but it's still kicking the start/stop on the high amp fuse:

if you have the tow package the fuse amps are:
B+, 150A, 150A, 100A, 125A, 300A Fuses.

if you don't have the tow package:
B+, 150A, 150A, 60A, 125A, 300A

If yours has failed, check the Z case fuse.

I am in no way stating to use a higher amp fuse in the jumper cable, as mentioned, you could do serious damage to the Jeep's brain
 

cozdude

Guy with a Red 2-Door
Jeep will replace my aux battery under warranty. I understand they will replace with stock Mopar battery.
Am I better off replacing the aux battery with a upgraded quality battery? Does anyone recommend the best battery to replace the aux battery?
I do hate the stop start feature. I turn it off and never use it. I do want to keep the system stock.
Thanks
Let them replace the battery under warranty. Then if it goes bad again (within the battery warranty period) there is a parts warranty on the battery. All you would have to pay is labor on replacement of the battery.
 

trailraider

Active Member
There is a very inexpensive way to get rid of the aux battery system.
And the expensive way.
This might be good to have in a tool box as an emergency item. But as said earlier in post, don't screw with the battery. They battery is there to make sure the system runs at a consistant voltage . It isn't even the price of the modules anymore that are my issue, if you pooch a module today it could be months before you can get a replacement.
 

Ikentrouble

New member
I plan on pulling both batteries and testing them both and replace what needs replacing. That being said what might be killing the batteries??? I'll admit I have no clue how these new systems work. With the sporadic way the system was working/not working, could I have a faulty PCR??? Im grasping at straws.
 
I plan on pulling both batteries and testing them both and replace what needs replacing. That being said what might be killing the batteries??? I'll admit I have no clue how these new systems work. With the sporadic way the system was working/not working, could I have a faulty PCR??? Im grasping at straws.
How many batteries have you gone through?
 
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