HELP! 2021 JLU Wont Start!

[jbennett_418]

If you start it with the extra battery and see 14.1 you’ll know it’s not the alternator. I’m putting money on bad cell. Winter months bring out the bad in batteries.

It currently ranges between 13.8-13.9V while at idle.

Sponsored

 

[Blanco Willys]

It currently ranges between 13.8-13.9V while at idle.

It’s close enough. With a DMM straight to the battery I bet it reads over 14v. It’s not your charging system. Definitely the battery.

 

[DavidArmen]

It currently ranges between 13.8-13.9V while at idle.

That’s totally normal because it has smart charging. The voltage will slowly decrease the more you drive in a particular day, so it doesn’t overcharge the battery.

 

[rhocking]

I am not sure if this is as good as disconnecting the battery and using a volt meter but if you press the start button twice without pressing the brake and then go to the same menu you are in for battery voltage when car is running I think you get the battery voltage without the alternator.

If anyone knows whether this test is not worth anything and the only way to check battery voltage independently is to use the volt meter let me know.

 

[jbennett_418]

I am not sure if this is as good as disconnecting the battery and using a volt meter but if you press the start button twice without pressing the brake and then go to the same menu you are in for battery voltage when car is running I think you get the battery voltage without the alternator.

If anyone knows whether this test is not worth anything and the only way to check battery voltage independently is to use the volt meter let me know.

That might work under normal circumstances, but since my Jeep was completely dead, there were no dash lights or gauges to look at.

Sponsored