98 jeep classic voltage gauge drops to 9volts after runnig for a few minutes,turn car off and then back on gage returns to 14v then drops again after a few minutes

 

Check voltage at the battery with a good voltmeter. The jeep gauges aren't exactly famous for their accuracy. If it still shows the drop, Awfulzone or Oreally will test the alt for free.

 

I have already been to awful zone auto parts,they did check it and the guy said,well it coud be the altinator,bad connections or voltage regulator

 

[QUOTE=jim1215;1633688]I have already been to awful zone auto parts,they did check it and the guy said,well it coud be the altinator,bad connections or voltage regulator,so I already know all of that

 

thank you for your reply,but yeah I already tried that,the guy checked with a voltmeter at the battery terminals and it was putting out 12.5v with the car running.he said it could be a bad connection or the altenator or the voltage regulator.so I noticed a bad connection at the battery post and replaced the old battery terminal connectors with new.after that my voltgage in the jeep jumped up from 12.5v to 14v,I drove it a few miles and it stayed at 14v,the next morning I drove it for awhile and it stayed at 14v,then the next time I drove it the gage in the jeep dropped to 9v.then the nexttime I drove it the gage was back to14v does this sound like a short or bad connection to you?

 

Sounds like the alt. going out to me. But I'd clean all connections and grounds before buying a new one. Is your alt. internally regulated, or does the PCM regulate it like on my '93?

 

I had almost the same problem, except my electrics went off on the road (that was a fun night...)
But anyway, all I did was buy a new battery and drive it around for a while. At first I had to pump the gas a little to get it to start, and keep the gas pedal down a little even when stopped, but after a couple weeks it sorted itself out and now she's running like new.

 

thanks for you help,but what is a pcm is that maybe the computer or brain box,and you know I am not sure if the voltage regulator is built into the altenator,but I kind of dont think it is

 

Did you find the solution? The PCM or powertrain control module regulates the alternator voltage.

 

what and or where is the pcm