Doug_the_chug

A week ago I was coming back from a weekend trip and noticed that the check gauges light was on with the volt meter reading 0. I made it back to town and have been driving without any issues, besides the volt meter reading 0 and check gauges light on. I replaced my battery connections, but hasn't helped. When I start up my JC the volt meter reads 11ish volts, then minutes later the gauge will change positions. 90% of the time will plummet to 0 and the check gauges light will come on and the other 10% of the time the gauge will go to 13-14 volts where it belongs. Any ideas? Thanks in advance.

jakbob

check your alternator

Doug_the_chug

That's what I was thinking, but correct me if I'm wrong...wouldn't my Jeep have died by now if the alternator was pooched?

TheNerd

...if its not intermittently failing, you can generally field-check your alternator by starting the Jeep and then disconnecting the battery (disconnect the + side). If the Jeep dies when you disconnect the battery, your alternator is the culprit. Of course, all of that may be BS since your volt meter is flopping from 0 to 13/14. The battery will run the Jeep for longer than you expect (at least longer than I expect)... but a whole week seems like too much. I guess it depends on how much you drive it.

Doug_the_chug

Cool, I will try this tonight and see what happens! Thanks!

tjwalker

Yikes, not a good idea to disconnect the battery on a running vehicle any longer. Might have been safe 30 years ago with the old points style ignition system; I remember using that technique on my 1966 Chevrolet!

I personally have repaired damage from somebody that tried this. Sometimes you get lucky and you escape damage, but don't press your luck as there are much safer ways of troubleshooting the charging system. Too many chips in the modern automobile that are susceptible to transient spikes.

Below is a link that explains why you shouldn't do this.
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http://www.troubleshooters.com/dont_...ct_battery.htm

Doug_the_chug

Hmmm, ok, I will have to rethink this one then. Thanks for the heads up.

Doug_the_chug

So on my way back from work yesterday night I could have swore my instrument panel light was getting dimmer. Thinking my eyes were playing tricks on my I pressed on. It fooled me for about 10 minutes until the instrument panel was completely dim and my headlights were non-existent. I made it to where I was going, but just barely! It was the alternator all along...

Thanks for all your input guys!

jakbob

15 minutes in an autozone parking lot could get the alt out and in for testing.