Won’t Start First Try

[JayInNC]

Out of the blue this morning, my Jeep wouldn’t start on the first try and now it consistently takes two/three tries. Had it checked at AutoZone and they said the alternator regulator is reading bad. Before I got home, I got the following warnings and now there are other things intermittently that aren’t functioning properly when I turn it on (park sense is a common one). Not sure if it is the alternator as the AutoZone guy suggested or maybe just the aux battery. So this leads me to a couple questions:
1. Anyone have any experience with this issue?
2. Ok to drive until I can get this addressed or could it possibly leave me stranded somewhere?

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[rent]

To help us help you, a little bit more info on your vehicle could be helpful. Year and engine configuration would be a good start. Did you get a read on the battery voltage?

 

[JayInNC]

2018 Jeep Rubicon. 13.2 volts currently. I didn't have them check the aux battery, maybe that should be the next step. One thing that's interesting is that it consistently won't crank on the first try...but it you press the button like you are cutting it off and then press it again, it starts right up.

 

[RoadiJeff]

Before you get too far into diagnostics, open the PDP and push down on every fuse and relay to make sure they are seated all the way. Even though yours is a few years old, a fuse or two could have worked its way loose.

 

[Gregj]

You have a bad auxiliary battery. The first time you try to start it it will test the aux battery and if it is dead it won’t start, if it is dead the second try will bypass that test and start anyway.
Gregj

 

[JayInNC]

Thanks. I isolated the aux battery and it’s at 11v. I was leaning towards that being the problem but the AutoZone testing had me second guessing…

 

[JayInNC]

You have a bad auxiliary battery. The first time you try to start it it will test the aux battery and if it is dead it won’t start, if it is dead the second try will bypass that test and start anyway.
Gregj

Thanks! It will be a couple days before I can get the aux battery changed. Any danger of being left stranded somewhere? Just trying to picture what happens if it goes completely dead while still in circuit, undue strain on the main battery/alternator, etc.

 

[Rhinebeck01]

@JayInNC

No question to it.... if your JL is starting on the 2nd try then the Aux battery hass reached the end of it's life cycle / is dead and needs to be replaced.. It is not the alternator..

Good news..... Your 2018 JL is behaving like a 2019-2021 JL.... it would not be exhibiting this behavior if not for sometime in the past it has had TSB 18-092-19 (Power Control Update) applied to it.. IF it did not your 2018 JL would not have started on 2nd try but would have just not started..

Best way to proceed for you is to replace BOTH the Aux and Main battery.. Do not just replace the Aux.. Do know that your 2018's Main battery is a time bomb of sorts, as it has aged out.

.

 

[Rhinebeck01]

Thanks! It will be a couple days before I can get the aux battery changed. Any danger of being left stranded somewhere? Just trying to picture what happens if it goes completely dead while still in circuit, undue strain on the main battery/alternator, etc.

@JayInNC

Sure, anything is possible..... Suggest you do NOT use ESS til you get this batter(s) issued taken care of. Be sure to push the ESS button each time you use your JL.

Also, would be a positive move to when the JL is just parked the next few days ... until you get the battery(s) issue addressed to hook it up to a battery tender maintainer. Hook up it's cables to the Main batteries Pos and Neg terminals..

Keep that Main battery from being stressed by ESS events and also maintaining that aging out Main battery will minimize chances of a no start situation while you are waiting to do the battery(s) replacement.

Is your 2018 JL, still under 36,000 mi / 3 yr. ?
.

 

[JayInNC]

@JayInNC

Sure, anything is possible..... Suggest you do NOT use ESS til you get this batter(s) issued taken care of. Be sure to push the ESS button each time you use your JL.

Also, would be a positive move to when the JL is just parked the next few days ... until you get the battery(s) issue addressed to hook it up to a battery tender maintainer. Hook up it's cables to the Main batteries Pos and Neg terminals..

Keep that Main battery from being stressed by ESS events and also maintaining that aging out Main battery will minimize chances of a no start situation while you are waiting to do the battery(s) replacement.

Is your 2018 JL, still under 36,000 mi / 3 yr. ?
.

Thanks! Nope, nearly 100k. Had to replace the main battery at about 60k. Kind of disappointing compared to some of the other vehicles I've owned.

 

[Rhinebeck01]

Thanks! Nope, nearly 100k. Had to replace the main battery at about 60k. Kind of disappointing compared to some of the other vehicles I've owned.

@JayInNC

Do your homework before changing out the Aux battery change... Do not .... do not change out the Aux battery by dismantling the Power Distribution Center (PDC) to get to the Aux battery.. You are asking for possible pricey problems doing so.. plus it takes a lot more time to do then the other two ways of accessing the Aux battery.

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

Since you Main is a replacement and fairly new, LOAD TEST it and decide if replacement is needed...

For Aux battery replacement:
Cost $110+-

DieHard Platinum AGM Battery, BCI Group Size 400, 200 CCA
Part # AUX14-1

Super Start Platinum Auxiliary Battery Group Size 400
Part #AUX14

 

[JayInNC]

@JayInNC

Do your homework before changing out the Aux battery change... Do not .... do not change out the Aux battery by dismantling the Power Distribution Center (PDC) to get to the Aux battery.. You are asking for possible pricey problems doing so.. plus it takes a lot more time to do then the other two ways of accessing the Aux battery.

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

Since you Main is a replacement and fairly new, LOAD TEST it and decide if replacement is needed...

For Aux battery replacement:
Cost $110+-

DieHard Platinum AGM Battery, BCI Group Size 400, 200 CCA
Part # AUX14-1

Super Start Platinum Auxiliary Battery Group Size 400
Part #AUX14

Thanks!

 

[Rhinebeck01]

@JayInNC

I linked to that thread I started in regard to changing out the Aux the easy way.. I have done it that way, the fender flare pull way a bunch of times... for other guys/gals that needed the Aux replaced...

I forget whether in that tread if I eve mentioned how the Dealer Techs do the Aux change...

Techs do it the way FCA suggests ... they cut a few plastic fender flare rivets, easily peel back the fender liner to access the Aux..

I myself find it easier/faster and less invasive, to do the flare pull, BUT.. but you need to have replacement $.99 fender flare clips to replace the couple you usually break when you pull the flare...

Anyway, you can do as the dealer Tech does... that way is easy also... Just go to Harbor Freight and buy the rivet gun they sell there. It comes with plastic rivets that will do the deed for your JL. The rivet gun cost is about $16+-. With that rivet gun you will be all set...

Remember when you change out the Aux battery to check and make sure the drain holes in the plastic Aux battery cradle/box are not plugged up... if so unplug.. 8-)
.

 

[JayInNC]

@JayInNC

I linked to that thread I started in regard to changing out the Aux the easy way.. I have done it that way, the fender flare pull way a bunch of times... for other guys/gals that needed the Aux replaced...

I forget whether in that tread if I eve mentioned how the Dealer Techs do the Aux change...

Techs do it the way FCA suggests ... they cut a few plastic fender flare rivets, easily peel back the fender liner to access the Aux..

I myself find it easier/faster and less invasive, to do the flare pull, BUT.. but you need to have replacement $.99 fender flare clips to replace the couple you usually break when you pull the flare...

Anyway, you can do as the dealer Tech does... that way is easy also... Just go to Harbor Freight and buy the rivet gun they sell there. It comes with plastic rivets that will do the deed for your JL. The rivet gun cost is about $16+-. With that rivet gun you will be all set...

Remember when you change out the Aux battery to check and make sure the drain holes in the plastic Aux battery cradle/box are not plugged up... if so unplug.. 8-)
.

Removing the fender flare seems way easier. Just saw this vid on youtube that gives some good detail as well...

 

[Rhinebeck01]

That video is lets say just ok.... misinformation and more... really lacking...

Read the at the thread I linked to... you will find pertinent info there that will make a difference in regard to your doing the deed..

Important....

When you get you new Aux battery home, immediately hook it up to a battery tender/maintainer that puts out no more them 5 amp max... Leave it connected to the tender/maintainer til the tender signals it is fully charged. It will take less then say a half hour with a 2-5 amp tender.. It will be ready/fully charged by the time you have the flare off.

You want JL fender flare clips. Have at least 6 handy... Do not try to use a JK fender flare clip. You can cut adapt the JL clips but a way lot of work and they may not hold as well after your adapt.

Read and be sure you read closely.... in regard to how to get the elec. connector to disconnect/to release when you pull the flare.. It can be a pain to release... Funny in the video they did not show you the process... what they went through to get it to release. Read at the thread I linked to so you know how to disco that connector without to much fuss

DO, have a second set of hands handy when you do the Aux swap. A teen or a Wife... even with no experience is all you need. Just hands to hold when you cannot or need assist at holding for a moment.

Loosen all battery box bolts a bit on the Aux battery box and then after they are all free, then remove each one.

CAREFUL not to let the battery box/ battery come flying down... a second set of hands comes in handy while you disco the battery from the cables..

About the stock Aux battery.... when you get it disconnected and out, carefully unscrew from both the Neg and Pos terminals, the metal post that is screwed into those two places... Now, take those posts and screw them into the Neg and Pos terminake of your replacement Aux battery. Do not try/both to use the connects that came with the Aux battery..

Be sure drain holes in the Aux battery holding box are clear.

DO, clean off the metal connect points/ ring connectors on the cables you will be attaching to the new Aux battery. Use some sand paper... clean them up.

Tighten but do not over tighten.. get crazy tightening the battery holder box bolts...

Anyway, the deed is not hard so do not let my yada yada scare you off... Just arm yourself with this info and some further reading and you will do aok.. Takes less fhen say 45 min, for a first timer.

Do others a solid and post in that thread I linked to earlier and here.... about your Aux battery change out experience.. We all learn from other's journeys.

.

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