Today I went to run some errands. First place I was at for about a half hour, second place an hour. I go back to jeep after an hour and when I turn it on I get a very quick flash of gauges then nothing. Everything is dead. I figure the battery is dead. I hook up cables to another vehicle and it doesn't turn on at first. After a minute, I turn key on, I get power, and turn on the engine. Disconnect everything and drive home. I turn the jeep off, let it sit a minute, and try to turn it on again. Nothing. No power, no click, no gauges. I hit the battery with the multimeter and have my wife hit the starter. No voltage drop at any point, battery holds strong at 12.6 volts, doesn't seem to be engaging. Is this a bad ignition switch? Curious as to how it was jumped if the switch is bad. Bad ignition ground? Going to start diagnosing it in the morning, wondering what direction to check first. Thanks in advance!

2014 Rubicon 3.6l with 5 speed auto trans.

 

If you try to jump it again does it do the same thing? If the battery is bad it may take a minute for the slave to charge it up enough to start. Since it ran Ok afterwards you can assume the alternator is working. The battery may have a bad cell since it doesn't do anything. Voltage is a piece to know but amperage is the key. You can also take the battery to most auto parts stores and they can test it.

 

I did check alternator before I turned it off. Solid 14.6v.

 

12.6 does not mean a battery is good. It is well established that our Jk's can do whacky things when batteries die, and they can die suddenly, which happened to me. I would do nothing until the real health of the battery was confirmed, as well as the battery connections. By health of the battery, that would mean a load test.