Fluctuating volatge at idle

[dbrown]

When driving, I’ve started to notice that when I come to a stop light, my voltage fluctuates from around 14.2 down to around 12. It sounds like the engine struggles to idle, then will ramp back up and sound fine. It’s only a year old, so hard to think it’s a battery already, but concerned about it nonetheless. Seems to be worse in the morning when it’s cold outside. Alternator? Normal?

 

[Robr651]

The OEM batteries are junk. Disconnect it and check it with a battery tester. I swapped mine out within 2 years as have many others. Some have had the dealer swap it under warranty. I didn’t want to waste my time at the dealer and my replacement has a 4 year warranty.

 

[dbrown]

That was sort of my thought as well; I had them test the battery at AutoZone, but I really don’t think the kid doing it had any idea what he was doing

 

[Firedude]

Mine has done this since new. Im going with normal.

 

[BarneyM]

When driving, I’ve started to notice that when I come to a stop light, my voltage fluctuates from around 14.2 down to around 12. It sounds like the engine struggles to idle, then will ramp back up and sound fine. It’s only a year old, so hard to think it’s a battery already, but concerned about it nonetheless. Seems to be worse in the morning when it’s cold outside. Alternator? Normal?

How old is your battery? My 2022 was doing something similar. I replaced the battery problem solved. May not be your problem but was mine.

It helps if you put the year of your Jeep somewhere in your post.

 

[Bobo57]

My stock battery took a crap about 14 months. No warning whatsoever, one minute starting and running normal, stop for 15 minutes totally dead. No dash lights, nothing...........
When that happened I did not observe any fluctuation in voltage behavior nor do I see that now. Interesting.

 

[hardhat]

The fluctuation at idle is likely the electric steering. Mess with steering wheel and you can provoke it.