Issues after changing batteries - FIXED

[The Last Cowboy]

I posted in the battery section about this and got no replies. I can't be the only one to experience this.

https://www.jlwranglerforums.com/forum/threads/issues-after-replacing-both-batteries.107802/

So, after replacing the batteries, the HVAC cluster has no power/function. Also, the A! light comes on and a message to service the ESS system.

I replaced the N1-N7 fuse cluster and tried a difference HVAC cluster, checked all the fuses and the issues persists. I really hate to have to go to the dealer. Anyone have an idea about this?

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[TimmH]

What method did you use for replacing the batteries, through the top or through the wheel well?

If through the top, make sure the fuse block connectors are tight and make sure no pins got bent.

If through the wheel well then check the connectors under there, particularly the one that is close to the firewall.

Double check the battery connections.

And you sure you got the N1-N7 connectors placed correctly?

 

[The Last Cowboy]

I went through the top. I’ll check for bent pins. Good suggestion, as I’ve triple checked everything else.

 

[CarbonSteel]

No help on the issue, but this is the very reason that I went through the bottom to change the auxiliary battery. I did not want to take a chance on any problems by going through the PDU.

 

[Htfan]

No help on the issue, but this is the very reason that I went through the bottom to change the auxiliary battery. I did not want to take a chance on any problems by going through the PDU.

Yes, going through the fender/bottom is the best way to get to the Aux battery. Just need to have a few extra plastic fender clips because breakage is probable.

 

[aldo98229]

I went through the top: zero issues. And didn’t have to deal with lining up the liner with the fender and replacing broken rivets.

OP: have you checked your charging? Some of the symptoms, like the ESS warning, sounds a lot like when the battery is not charging properly.

You might have gotten a bad battery. It does happen...

 

[Swisskidd]

Isn’t the secondary battery fuse- protected, when the main battery cables are removed and the positive lead inadvertently touches a ground nearby (shortening out the secondary battery)? Any chance that fuse is blown?
No personal experiences as of yet, outside of helping a friend replacing his secondary battery (after his main was replaced 3 months earlier). Did a lot of reading on this forum and kept the main battery leads isolated during the swap.

 

[Dgr401]

Yes, going through the fender/bottom is the best way to get to the Aux battery. Just need to have a few extra plastic fender clips because breakage is probable.

How many clips are there on the front fenders?

 

[Htfan]

How many clips are there on the front fenders?

Good question. Here's a great thread on Aux battery replacement with a video. You may be able to get a clip count.

https://www.jlwranglerforums.com/fo...ent-the-easy-way-pull-the-fender-flare.56807/

 

[CarbonSteel]

How many clips are there on the front fenders?

You do not have to remove or replace any of the clips nor remove the fender or the passenger tire, you only have to replace some of the rivets that attach the liner to the fender.

1. Turn the passenger tire fully to the left.
2. Drill out the first 5-7 rivets using a 1/8" drill bit, starting at the bottom of the passenger fender--be sure not to drill too deep so that you do not punch through the fender. It does not take much drilling before you can just pull them out.
3. Remove the "Christmas tree" fasteners with a body tool.
4. Remove the bolts attaching the fender liner to the fender (5 if memory serves).
5. Peel back the fender liner towards the front of the Jeep using a bungie cord to hold it in place (I used the bumper as an anchor point).
6. Remove the two bolts that hold the battery box to the bottom of the PDU.
7. Remove the auxiliary battery and disconnect.
8. Reverse the installation steps.


Rivets - https://smile.amazon.com/gp/product/B07D6JXC4Q

Rivet install tool - https://smile.amazon.com/gp/product/B007QV2E50

I can assure you that going through the bottom is the fastest, easiest, AND safest way to change the auxiliary battery. You will be drinking something cold while the "going from the top guy" is still pulling things apart.

 

[cram501]

I found removing the fender and liner as one was pretty easy. You need to replace one push pin and any fender clips broken during the removal. I thought it was easier than removing and replacing the rivets.

 

[The Last Cowboy]

What method did you use for replacing the batteries, through the top or through the wheel well?

If through the top, make sure the fuse block connectors are tight and make sure no pins got bent.

If through the wheel well then check the connectors under there, particularly the one that is close to the firewall.

Double check the battery connections.

And you sure you got the N1-N7 connectors placed correctly?

Thanks Tim,

I went back today and removed the PDC/fuse box. I unplugged the 4 large harness connectors under it and found a bent pin at F105 ICS/HVAC. I was able to straighten it out fairly well with some needle nose pliers. I carefully reassembled the PDC and everything functioned properly afterwards. No lights or malfunction messages.

I’ve become quite familiar with the system after dealing with this issue. I find that it is not that difficult going through the top to get to the aux battery, but there is a lot more risk for damage to the pins or to the N2-N7 fuse array. Many who have weird issues are going to have either bent pins or a blown fuse on the array.

The preferred way to get to the aux battery will be from the bottom. That way the risk of damage is significantly reduced. I’m sure if I took this back to the dealer, they would have had it for days or weeks, and would have gladly charged me $800 or so for a new PDC.

 

[TimmH]

Glad you got it worked out.

 

[mwilk012]

I went through the top. I’ll check for bent pins. Good suggestion, as I’ve triple checked everything else.

Everyone who has ever suggested this method should have their posting privileges revoked.

 

[aldo98229]

Thanks Tim,

I went back today and removed the PDC/fuse box. I unplugged the 4 large harness connectors under it and found a bent pin at F105 ICS/HVAC. I was able to straighten it out fairly well with some needle nose pliers. I carefully reassembled the PDC and everything functioned properly afterwards. No lights or malfunction messages.

I’ve become quite familiar with the system after dealing with this issue. I find that it is not that difficult going through the top to get to the aux battery, but there is a lot more risk for damage to the pins or to the N2-N7 fuse array. Many who have weird issues are going to have either bent pins or a blown fuse on the array.

The preferred way to get to the aux battery will be from the bottom. That way the risk of damage is significantly reduced. I’m sure if I took this back to the dealer, they would have had it for days or weeks, and would have gladly charged me $800 or so for a new PDC.

Glad you resolved the issue!

You might want to edit the thread title to read [FIXED] to help other forum members.

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