Alternator?

[Klevenson]

2021 Rubicon is undrivable. 13k miles. Check engine light. Then non essential battery uses shut down. Then sway bar! Warning. Then a big clunk sound and it was dead. Of course, the warranty ended in 10/23. One tow guy thought it might be the alternator. I will see a mechanic in a few days, but, a

Sponsored

 

[Kbinspections]

Have you replaced the batteries?

 

[oldcjguy]

You should still be under warranty. Drivetrain should be 5/60. 3/36 is bumper to bumper. That said, have your batteries checked, both primary and secondary. Have them load tested at Autozone or something. With so few miles, it sounds like the jeep may sit a lot. Also, 3 years seems to be the average of when people start having battery problems. All kinds of weirdness when the battery goes bad.

 

[Rhinebeck01]

2021 Rubicon is undrivable. 13k miles. Check engine light. Then non essential battery uses shut down. Then sway bar! Warning. Then a big clunk sound and it was dead. Of course, the warranty ended in 10/23. One tow guy thought it might be the alternator. I will see a mechanic in a few days, but, a

Seriously doubt the issue is related to a problematic alternator. It probably is a battery(s) relatedc issue and no more..

The "tow guy" is not up to speed lets say.... in regard to the JL's dual battery system.

Careful paying out $ to mechanic(s) that are not JL, battery system savvy.

My guess is your issue will be remedied by the replacement of both the Main and Aux. batteries if you have a dual battery JL or just changing out the Main battery if you gave an etorque JL.

 

[Beachcomber72]

2021 Rubicon is undrivable. 13k miles. Check engine light. Then non essential battery uses shut down. Then sway bar! Warning. Then a big clunk sound and it was dead. Of course, the warranty ended in 10/23. One tow guy thought it might be the alternator. I will see a mechanic in a few days, but, a

What engine do you have? 3.6 or 2.0 and also is it with or without Etorque?

 

[Klevenson]

Seriously doubt the issue is related to a problematic alternator. It probably is a battery(s) relatedc issue and no more..

The "tow guy" is not up to speed lets say.... in regard to the JL's dual battery system.

Careful paying out $ to mechanic(s) that are not JL, battery system savvy.

My guess is your issue will be remedied by the replacement of both the Main and Aux. batteries if you have a dual battery JL or just changing out the Main battery if you gave an etorque JL.

The first tow guy tested the battery. Battery was good. Alternator was in the yellow warning zone on his tester.

 

[Bill_BCNtoNY]

I could be wrong, but I doubt the tow guy did a load test on the battery right there. Not impossible, but seems unlikely.

Here are some possible next steps I would suggest:

1. Confirm engine and battery setup:
   • Is it a 2.0 gas, a 3.6 gas or a diesel?
   • Does it have e-torque (mild hybrid)?
   • Is/are the batteries original? both the main and the aux (the small one under the big one, if you don't have e-torque)?
2. Consider/research other battery setup options, such as bypassing/deleting the aux battery if you have that, or installing a kit from Genesis for dual batteries or at least for easier access to the aux
3. Replace any batteries that haven't been replaced yet (applies to the main and aux batteries, not the e-torque if you have that)
4. Load-test the batteries - I had one fail within 3months of buying it. not super common, but that happens particularly with MOPAR/OEM brand batteries
5. Don't hesitate to come back and ask more questions here in the forums - batteries give plenty of headaches in our JLs and we'll be happy to help if we can!

 

[4xFUN]

What did you find out? As EVERYONE has said check BOTH batteries! That IS the problem 90%+ of the time. Good luck!

 

[Upnarms]

One thing to look at in the alternator. I agree with everyone to check batteries first, if you have the aux change both or so aux delete. But check your alternator pulley to make sure the decoupler didn't lose all it's grease. If you ever see a line of oil or grease around the engine, across the underside of the hood, the decoupler could have blown the seal. Happened to me but didn't cause any breakdown. I read somebody's died when they ran it with no grease left in the decoupler pulley, fried the alternator i guess.

If for some reason you do have a bad alternator which is unlikely, they are very easy to swap out yourself.

 

[Klevenson]

I could be wrong, but I doubt the tow guy did a load test on the battery right there. Not impossible, but seems unlikely.

Here are some possible next steps I would suggest:

1. Confirm engine and battery setup:
   • Is it a 2.0 gas, a 3.6 gas or a diesel?
   • Does it have e-torque (mild hybrid)?
   • Is/are the batteries original? both the main and the aux (the small one under the big one, if you don't have e-torque)?
2. Consider/research other battery setup options, such as bypassing/deleting the aux battery if you have that, or installing a kit from Genesis for dual batteries or at least for easier access to the aux
3. Replace any batteries that haven't been replaced yet (applies to the main and aux batteries, not the e-torque if you have that)
4. Load-test the batteries - I had one fail within 3months of buying it. not super common, but that happens particularly with MOPAR/OEM brand batteries
5. Don't hesitate to come back and ask more questions here in the forums - batteries give plenty of headaches in our JLs and we'll be happy to help if we can!

Thank you! I will ask him to change out both batteries. They are currently the original batteries. The Jeep was my fun car for the weekends until 10/23 when it became my only car to commute to work. It has only done a few 400+ mile trips.

It is not Diesel. If I stop for a short amount of time, it sounds like the engine has shut off.

 

[Bill_BCNtoNY]

Thank you! I will ask him to change out both batteries. They are currently the original batteries. The Jeep was my fun car for the weekends until 10/23 when it became my only car to commute to work. It has only done a few 400+ mile trips.

It is not Diesel. If I stop for a short amount of time, it sounds like the engine has shut off.

this sounds like you have the auto start/stop function enabled; it saves a bit of gas in town and it is quite hard on batteries.

I think the issues can be avoided totally by (1) turning off auto start/stop, (2) getting better quality batteries and (3) deleting the aux battery, or minimized by doing only a subset of the three.

Also, you can completely replace the battery system with a Genesis Dual Battery System - expensive and overkill for almost all of us, but well-built and effective.

Keep us posted on how it all goes!

 

[58Willys]

If you have a non e-torque Jeep, separate and load test each battery separately. If one is bad, replace both. Test alternator; should have 13.4 - 15.4 volts across the batt terminal. Check battery cables and grounds.

 

[JPAloha]

Be wary of analyzing the alternator based on traditional output range tests.
I learnt, last year, that the JL’s have an intelligent charging system I.e. the alternator puts out what the batteries need and nothing more.
Batteries are low, it will push out 14.x Volts, batteries are fully charged you’ll see alternator readings in the 12.x Volt range.

 

[Klevenson]

Have you replaced the batteries?

Batteries were fine

 

[4xFUN]

Batteries were fine

So what was the problem? What type of shop did the diagnostics and / or repair?

Sponsored