I started my jeep up tonight and started driving home and the voltage gauge went to 0 basically - my 97 reads 9-19v, I drove it home lights didn't dim, seemed to run fine the whole way home. Does the Voltage gauge on these run off the alternator? I'm gonna check that first in the morning.

Is there anything else I should look at?

Thanks for the help in advance.

97 XJ 4.0 Auto is the info

 

Sometimes the speed of the blinker works as a volt meter of sorts. If it's slow, then speeds up when you start it your charging. Sounds like your gauge gave out or is not getting power. All else is fine? The alternator is connected to the battery and the system, as well as the gauge. At 10 volts you would know it's not right. 0 is not really an option. Bad grounds seem to come up allot. I think the gauge shares grounds with other stuff. You pretty sure everything else is working? Anyway stop by somewhere or pick up a cheap meter and see that you are running at or over 13.5 or so. Over 14 to 14.8 is fine too.

 

After brushing the snow off of it this morning, I checked the battery cables, looked clean not corrosion. One was a bit loose so I tightened it up, put my voltmeter on it and the battery read 12.2v. Well within the norm as far as I've seen, started it up, gauge worked fine, and had 14.+ across the battery per my meter so the alternator is definitely charging. Some how, the connection must have come a bit loose, everything looks good as far as I can see now.

 

Ok,more info on the issue

It happened again today while just leaving my house, I turned around put my volt meter across the batt terminals, read 14.2 volts, while running, so the alternator is charging. I turned the jeep off, battery voltage was fine still over 12v

Started it back up, volt gauge came up halfway, sat for a min or so, then went to 14v, hmmmm

Driving home from work, gauge did the same came halfway up, then went to 14v

Shut it off, ran in gas station, started it back up and gauge was fine, check engine light came on, ran the OBDII codes. First time the dummy light has came on.....

Came up with these

12 Battery or computer recently disconnected

24 Throttle position sensor over 4.96V

47 Battery voltage too low and alternator output too low

Any suggestions on where to start?