Battery light on, but showing 13.67-13.74

'02 Liberty, Ltd. v6, auto.

Battery light came on, on the way home. Bringing up the RPMs in neutral to 4k did not make it go out. Am showing 13.6-7 on my volt meter across the battery terminals with the engine running. I would not expect that high a voltage if it were not charging, would I?

Vehicle has been starting fine, not sluggish.

Any thoughts?

What is it measuring when the truck is turned off?
Try this also with the headlights on (truck still off) and see if it drops.

2 Easy Ways to Check a Car Battery (with Pictures)

I'm not positive but I seem to remember that on an 02 you may get a battery light if the temp sensor under the battery is failing or sensing an overtemp. I'd be most suspicious of the battery and have it load tested.

Battery temp sensor should set a code. P1492 I believe.

ltd02 said:

I'm not positive but I seem to remember that on an 02 you may get a battery light if the temp sensor under the battery is failing or sensing an overtemp. I'd be most suspicious of the battery and have it load tested.

Battery temp sensor should set a code. P1492 I believe.

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That ^^^^

If the battery is carrying that voltage with accessories and lights on then the battery temp sensor is bad - or your battery is getting hot for some reason.

Bob

Check for the stored OBD2 trouble codes if the light is on.
13.6 volts vehicle running for a charge is a bit low. I see 14.2 on mine cold, no lights on.
How old is that battery? As mentioned get it load tested!

LibertyTC said:

Check for the stored OBD2 trouble codes if the light is on.
13.6 volts vehicle running for a charge is a bit low. I see 14.2 on mine cold, no lights on.
How old is that battery? As mentioned get it load tested!

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Yeah, mine will read between 14.2-14.5 with engine running/driving with no lights according to my scan-gauge.


Dave

Thanks for all the thoughtful responses, guys! The battery was 7 years old, and with the out-gassing/corrosion issue needed to go anyway, so I replaced it this morning. No battery light now, but I am NOT a fan of fixing things by randomly replacing parts. Had the battery been newish I would have attempted more of a real diagnosis.

We'll see how it goes.

Glad new battery solved battery light/code.
If you got a new lead acid battery, to prevent terminal corrosion, for $5 go get some felt battery terminal washers.
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^These were installed on factory install, but eventually fall apart.
Also use some Vaseline to terminals.
It is important to keep the terminals clean, and the felt washers do help!
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Of course the best batteries are not lead acid as AGM types are fully sealed, and offer a stronger case for off road. :gr_grin:
For a few extra $ the AGM- absorb glass matt batteries are a good choice.
Odyssey is the best but under the hood, I have an Excide AGM.
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make sure to get your alternator checked as well.

^ good idea!
I load test the battery once a year, and use the VOM frequently with Jeep running.
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14.2 is a good sign that the battery is getting a proper charge! :gr_grin:

My mechanic that I go to for advice and is a jeep certified mechanic said that the voltage should range between 13.8 and 14.2 Volts. If you have done the external regulator modification then it should be around 14.6 volts.