highmileage

At nite my voltage will read anywhere from 11.5 to 12.8 volts with the headlights on with the fan running on hi volts drop to 11.3 and sometimes dip to 10.9ish.
these are the readings from my handy cigarette lighter tool.
At the battery volts read 14.4 just as it should be, this is how the elec system has been reading, since I got my jeep 7 years ago, and did not change with an alternator swap. The stereo most likely does not help with any of this and much like in the days of the cars that go boom so does the electrical (you may want to look at a dual battery setup)

salad

lol yes. I actually hurt myself laughing one day at this Cavalier that had a big sound system without putting any thought into it. Sub caused the entire car to resonate. Each thump was mixed with rattling body kit, I thought it was going to fall apart when the light turned green lmao

NoClearCoat

I'm 23 and LOL guys. It's worse when some DA leaves his crap on with the whole car rattling, windows down and walks into the store to pay for gas. He's thinking, Look at me! I'm soo cool! To the rest of us, the message is Look at me! I'm an inconsiderate *** gasket who wants to be deaf! Over on Crownvic.net this one guy wanted to bypass the inertia switch in the trunk (thing that kills the fuel pump in a hard collision) because it kept tripping due to his system. Responses ranged from "turn the volume down" to "go ahead and bypass it, the doors will be wedged shut in the crash, pump keeps running and there's a big fire and no one will hear you screaming for help over your "music" Btw I had no part in that thread.

To OP, check the pitifully small output wire on the alt. and of course all the grounds to engine/chassis, and the dash voltmeter is really inaccurate on my jeep. 14 volts at gauge, 14 at battery. 9v on gauge, 12.4 at battery with all lights, fans, OBA, and electric cooler running. all mesurments at idle

cruiser54

For you Renix guys, and maybe later models too, this works well to improve instrument gauge accuracy.

Improving the Instrument Panel Ground
The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release ****. The screw will have either a ¼" or 5/16" head on it.
This ground point is responsible for handling the ground circuit for the following items: Dome lamps, Seatbelt and key warning, trans comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.
The problem is that where the ground point is located does not have a good contact with the chassis where the ground should be. The solution is simple.
Make up a jumper wire with #10 gauge wire about 10" long. On one end, crimp on a ¼" round wire terminal. On the other end, crimp on a 3/8" round wire terminal.
Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
Look above the driver’s side plastic kick panel just forward of the top of the hood release ****. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.
**Special note for Comanche owners: Make your jumper wire 12" long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**
　
Revised 11-29-2011

NoClearCoat

Good info, thank you very much, Sir. Off to find my strippers and crimpers.

highmileage

Thank you cruiser, I'll give it a go

cruiser54

Please report back regarding the results.

stev-o

I seem to be holding 14v now that I tightened the connections on my starter relay might get a new alt soon just as a precaution

cruiser54

That was a good idea.