Need Help, replaced batteries and wont start. Can't find problem after 2 days of trouble shooting

[Sublime]

Before you ask, Yes I searched the forums and online and have tried what I could find.

Prolem- Aux battery drained Main battery.

Fix - Replaced both batteries, didnt want ti do delete

Method- sadly went from the top and removed fuse box. Followed video and seemed easier for me than removing my wheel and wheel well.

Put everything back and connected all wires correctly tried to start and lights everywhere and finally said needed to be in park (which it was) so had power, lights, dash etc worked but no crank.

Next disconnected main battery because there was a buzzing noise coming from engine bay that stopped after about 15 minutes.

Researched possible problem with Z fuse. Tested that with multimeter and have continuous circute.

Tried to start again a little later after making sure everything was snug. Dash lights uo when I open door but start button shows no lits for aux or run and no crank. Dash says press brake and push start button.

Disconnected IBS wire for 15 minutes. No chnage.

Tested all small fuses in fuse box and all have continuous circute.

Decided to try aux delete by pulling fuse 42 and separating grounds. Kept thicker ground wire to battery and taped and tied off thinner ground. Same issue

Disconnected main battery, pulled up fuse box again checked all wiring under box for potential loose wire, all good. Checked all pins to see if bent and all good. Pulled them up and accessed aux battery again. Removed aux battery completely. Taped of aux battery power and negative separately.

Tested main battery shows 12.48.

Any help would be appreciated. Again I've researched but can't seem to find anything at this point beyond what I Tested. A battery change shouldn't be this hard. SMH

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[Mr._Bill]

Did you fully charge both batteries before installing them?

A fully charged AGM battery should read 12.8 volts with no load on it.

 

[Sublime]

No I didn't. Never knew to charge a battery when installing new

 

[Mr._Bill]

I would suggest starting with a full charge of the Main Battery, using a AGM charger, and a IBS reset.

 

[Free2roam]

I never charged my batteries when I installed. Odyssey 94R and new ess battery. Not one problem ever. I've heard you should charge them. But I don't have a charger.

 

[Mr._Bill]

I never charged my batteries when I installed. Odyssey 94R and new ess battery. Not one problem ever. I've heard you should charge them. But I don't have a charger.

There are a lot of variables, including how charged the battery was when it left the factory, and how long it sat before it was installed. Many drive their vehicle enough that the batteries will get charged within a few days. Without fully charging the batteries and resetting the IBS, it takes longer for the IBS to adjust to the replacement battery.

 

[Sublime]

I would suggest starting with a full charge of the Main Battery, using a AGM charger, and a IBS reset.

Can i just jump it with one of my other vehicles to get it started? Don't have an AGM charger.

Also for IBS reset what is the legnth of time. I've seen 30 seconds, 15 minutes, 1 hour?

 

[Mr._Bill]

Can i just jump it with one of my other vehicles to get it started? Don't have an AGM charger.

Also for IBS reset what is the legnth of time. I've seen 30 seconds, 15 minutes, 1 hour?

I would give it five or ten minutes. The amount of time it takes to replace the battery is more than enough.

Using another vehicle should get it started, but it will take a lot of driving to charge the battery.

 

[Lost1wing]

I don't know your method of testing the fuse array, but you just can't probe the terminals for 12vdc. You will need to disconnect the cables and check for continuity across each fuse.

If you left cables connected and simply disconnected the posts on your first attempt, it is possible that you have drained one of your batteries before you even reconnected the other. To prevent this, the fender ground cable must be disconnected. It should be the last cable to reconnect.

Start over! Charge each battery with an AGM charger. You can get away with using a standard charger if that is all you have. You are not doing a favor to your new batteries however. While you are charging the batteries, pull the fuse array and check continuity on each fuse. Verify each cable goes back on the correct terminal. I've seen these cables in the wrong position( all off by one) or just one or two swapped.

Keep those cable ends isolated from everything. After verifying all connections are secure, the last connection should be the fender ground cable. It doesn't matter which end you disconnect.

 

[Sublime]

I don't know your method of testing the fuse array, but you just can't probe the terminals for 12vdc. You will need to disconnect the cables and check for continuity across each fuse.

If you left cables connected and simply disconnected the posts on your first attempt, it is possible that you have drained one of your batteries before you even reconnected the other. To prevent this, the fender ground cable must be disconnected. It should be the last cable to reconnect.

Start over! Charge each battery with an AGM charger. You can get away with using a standard charger if that is all you have. You are not doing a favor to your new batteries however. While you are charging the batteries, pull the fuse array and check continuity on each fuse. Verify each cable goes back on the correct terminal. I've seen these cables in the wrong position( all off by one) or just one or two swapped.

Keep those cable ends isolated from everything. After verifying all connections are secure, the last connection should be the fender ground cable. It doesn't matter which end you disconnect.

Thanks. Yeah when i checked the fuse array I did not pull so i can see where that could still be the problem.

No I had not disconnected ground from the fender well but 99% sure everything was good. But will check fuse array to be sure.

AT this point i think i will try to jump it to see if that can at least let me start it. If nothing i'll go through the process of disconnecting the fuse array.

I'll also pick up an AGM charger on the way home.

 

[Sublime]

Ok tried to jump with wife's car still no luck. Maybe i did t leave it on ling enough. I only gave it a minute or 2 since I had lights everywhere else on the jeep. No luck.



Disconnected battery amd pulled fuse array. Checked each tab with multimeter. All good.



Also since I didnt have any light on the start button, I pulled that fuse and was fine.

 

[Sublime]

Just checked all replays and all seem good. Going to get an AGM charger tomorrow.

 

[Bandit’s Lair]

Just checked all replays and all seem good. Going to get an AGM charger tomorrow.

Harbor Freight has a 4A charger for a pretty good price. Takes a while to charge but it does the job. Mine is charging a new battery right now. .

 

[DylanM]

IMO, an AGM battery at 12.48V is just under 80% state of charge which should be plenty to get your Jeep to start and run. Not saying it's not worth your time charging the batteries, but I don't believe that in and of itself is the cause of your problems here.

Regarding the lights on the ignition switch not coming on: if you have power locks, do they respond and function normally to inputs from your key fob? Are you absolutely certain you're getting power through N1 at the PDC? Are you absolutely certain you're getting power through fuse 10 in the PDC?

 

[Lunentucker]

I just came here to say that it's a good thing you replaced the auxiliary battery. It's what keeps the sensitive electronics stable.

Good luck!

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