spartan99

My battery will not hold a charge and I think I have a voltage leak. Any help would be appreciated as I am no expert in diagnosing electrical issues, but I am eager to learn.

I removed the ground cable from the negative battery post, and am completing the circuit with my multimeter by connecting one lead to the detached ground cable and the other lead to the negative battery post.

With my multimeter set on ohms, I get a reading of either 6.75. Is 6.75 normal? I figure there must be some draw with a computer, clock, etc. Or shoukd it be 0?

2008 JKUX no power anything no cruise control nothing but the base model.

Thanks in advance you folks are always very helpful.

rob_engineer

Dumb question, but did you get your battery tested? A bad battery is surely a likely cause. At rest, the voltage on your battery should be around 12.6 - 12.8. While running it should be around 14. You need to take your battery to an auto parts store and have it load tested. They do it for free. I've never heard of doing and ohms test on a battery. A multimeter applies about 5 volts on the leads when testing for ohm. So you are taking a 5 volt supply and touching it to a 12.6 volt supply. Makes no sense to me.

rob_engineer

Instead of ohms, when you disconnected the neg terminal you could have put your meter into ammeter mode and measured the current flowing. Though I don't know what a "good" reading would be for that.

spartan99

Thanks. The battery is only a few years old so I haven't checked it yet. I'll try that next. I don't have an amp section on my mm. Just volts and ohms. I guess I need a better mm.

This was so helpful.


https://www.jk-forum.com/forums/jk-e...aining-333220/

Mark Doiron

Obviously you are not an expert. Please don't hook up your VOM like that again unless you're certain what you're measuring and how you're measuring it. Had there been, say, a 25-amp parasitic drain you could have had a lot of sparks, burned up some wiring, and started a fire. It's also an easy way to damage the VOM.

Ron continually provides great advice.

spartan99

Good to know.

spartan99

According to Ronjenx, a good reading is 5-35 milliamps.



"Normal drain of a JK that has gone to sleep is from five to thirty-five milliamperes.
It takes about 5 minutes for all the computers to shut down after the ignition switch is turned to OFF.

Disconnect the battery negative cable and place the leads of an ammeter between the cable and the battery terminal. Wait 5 minutes and note the draw. Make sure not to lose continuity. If you do, the 5 minutes starts over when you reestablish continuity.

If you see more than the normal five to thirty-five milliamperes, start pulling fuses and reinstalling fuses, one at a time. If one causes a significant reduction in the amp reading, that's the circuit you need to look at.

If no fuse shows a reduction, pull the alternator lead and see if that shows a reduction."

spartan99

Battery was the culprit. It was much older than I remember. Amps tested within limits using a MM.