Ok, please help me with this, I have yet to find any threads with this exact problem. So, for the past month or so I have had issues with voltage. Sometimes I start the jeep, perfect 14 volts. Other times and it was the most frequent, I would start it, it would stay around 11 volts, I would drive it for a bit...it would jump up, then about a week ago it only hovered around 10 volts...then the battery went dead...it was 6 years old so I replaced it, and I replaced the alternator...now I have nothing...is it possible I fried the battery because I drove it for almost a week on battery alone. Could it be I got a junk alternator or both. I checked all the grounds, positive cables...there is signs of corrosion under the cable jackets on almost all the cables, and I have a small oil leak and noticed some residue covering the terminals on the starter. I plan on getting all new cables tomorrow and replacing. I also looked for a fusible link...wtf...I also read it could be the pcm. Looks like I am buying a volt meter as well....please help....I also have a transfer case issue I posted a few days ago, please read that as well...

 

Anyone?

 

I had a similar problem and it ended up being the alternator. After taking it apart I found that the brushes were all the way outand would intermittently loose contact with the shaft.
I woul dbe driving, fine, 13v, all of the sudden, 12, then 0. restart the engine and it would be fine. kept going on.
I rebuilt the alternator and its been fine.
It could however be a battery problem. It could have a shorted cell, or a loose cell that shorts against another.
you have to try and get the problem to happen, and then check voltage. Check right at the positive stud of the alternator. If the gauge is reading 10, and the alternator is putting out 13, then you cane move down the line.

 

I've noticed the voltage needle moving around quite a bit on my Cherokee as well. It will be up at 14 and then lower down to the top of the red zone. I haven't had any issues with the battery dieing so i haven't investigated further.

 

Year of your Cherokee? Makes a difference.

 

Here's a good thing to do on your 90 for the gauges.

Have you ever done a good ground refreshing/upgrade on it?

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

 

Ct 67 72 has a good idea. I had issues with an alternator as well. I replaced it only to keep on having issues. I brought it back and asked the store to check the new one before I installed it again. Long and short of it was we went through 3 of them before I found a good one. These were new alternators too, not remanufactured ones.

 

Mine is a 95, sorry I didn't mention it in the first post. I am gonna start with replacing all the cables since there is corrosion, I am gonna buy a volt meter and a charger and check everything with a charged battery, and go from there. I am frustrated cuz I had to borrow my grandparents van to have a 2nd vehicle, my grand prix needs the intakes done, and now the jeep is acting up...thanks again, any more suggestions is beyond appreciated

 

Good plan BTW.

 

Thanks for the grounding information Cruiser. I will do that as well as cleaning all the grounds in the engine compartment as i've seen you post about in other threads.

 

I have had tons of problems and strange symptoms from bad grounds (there has got to be 1000 under the hood).

 

Can't hurt and will probably nip a problem or more in the bud. Go for it.

 

Well, took me about 2 hours, but I replaced as much as I could wiring wise, went back and added dielectric grease to everything to keep moisture out...hooked battery up...turned ignition...full 14 volts, I think my blower motor and resistor are dragging voltage down, so those are next...thanks for the advice..

 

I love hearing that. Keep up the good work.

Try this for the volt gauge dipping alot with teh blower on while you're at it.

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