Im having some intermittent charging issues. When problems occur while the car is running, I will first see voltage on the dash drop from 15 volts to ~12-13. Then it may jump around for a bit or stay at that level. Sometimes if I hit a bump, the voltage will jump back up to 15. occasionally it will begin overcharging until I turn on an accessory to bring voltage down. Had alternator tested and it is good, both incar and out of. Battery is a little old but still good. On the alternator itself, there is a black plastic connector. Two terminals on this plastic connector are directly connected by a thick short piece of wire with a wire but on the wire. Is this wire supposed to be there, I wouldn't think the wire nut is though. Any other input would be helpful, battery connections are tight, grounds I have found I sanded and tightened (battery ground and strap from head to firewall). My guess is this wirenut is the issue or the voltage regulator is intermittently failing. Thanks

 

You'll have to tell us what Jeep you have, what year, and what engne.

Take and post pictures if you can.

 

95 Cherokee sport with inline 6