1998 Jeep Cherokee Not Charging Battery

[Don M]

I have a 1996 Jeep Cherokee with the same problem. Will all the above apply

 

[carnuck]

did you check volt reg inside alt there known to be bad even new ones fail sometimes

On newer Jeeps, the regulator is not in there. Newer Jeeps are controlled totally by the computer, including the alternator. The bad ground wire caused an open circuit, which meant the alt thought the battery was dead and pumped all the juice it could, thereby frying the rectifier in about 1 minute. (sometimes less)

 

[brandonmed]

i have read this post inside and out. i believe i have done everything i can to this jeep and nothing is working. This Jeep really is possesed. One day it is fine another it wont charge. My gauge will say just over 9 volts on the instrument panel. I will drive for a few minutes and the gauge dies and the check gauges light comes on. I know at that point that i am just running off the battery. on occasion while this happens and my battery is being drained the check gauges, as well as all other light, will dim out. all of a sudden while driving in notice the check gauges light will all of a sudden brighten up. If i shut the car off and restart the car the car will be perfectly fine and charging with the gauge saying 14. i just dont get it. Yesterday i was tooling around perfect, then the next time i hop in and start it up and i will get no charging. I have pulled the alternator 3 times to have it checked at different places. I have pulled it when it was not showing a charge and when the car was perfectly fine just to make sure. Everyone testing it says it is perfect. It is the 130 something volt alternator. The battery has been tested and thet is supposedly perfect too. i have gone through all wires and even replaced the grounds. i had some crappy terminal ends on the batery so i even replaced them too. Can someone honestly tell me whats going on? Why would it be fine one second and dead the next. I have even set my iphone up to record video of the gauge while i have gone under the hood to play with wires, just to run back into the car to watch a video of the gauge never showing any improvement. Help Help Help!

 

[carnuck]

Like I said, the main computer controls the alt. It gets corrosion inside and the drivers go bad. It's so common that it should have been a recall.

 

[brandonmed]

Is there anyway i can bypass that side of the computer and add an external voltage regulator? im sure a wire comes in to the computer and exits the computer to control that so i should be able to pull the wires i need. I am really tired of always having an issue with this. I would just need to know which wires to do this. I am really tired of throwing money at this issue. I have been pretty good at keeping this thing alive for the last 250,000 miles while keeping the price down. Thanks.

 

[carnuck]

Yes. Find the 2 field wires going into the alt (one has power with the key on and the other was grounded through the computer) and use a '77ish Dodge regulator and plug. The body of the regulator needs a good ground and 1 wire has power with the key (Tee off the incoming one to the alt) and the other grounds the second field wire on the alt.

 

[brandonmed]

Well I finally straightened it out. It ended up being a bad alternator. Even though I had my original one tested 3 times and they said it was good. I replaced it with one I pulled out of a parts car and charging fine now. Luckily a friends niece had the same car but totaled it a few weeks back, no one was injured. I tried her computer first seeing how it was the easier swap. No change came out of that so I swapped back my old one and swapped the alternator. Good as new and was very happy to get my jeep running for some snow fun in the north east. 253,000 miles and going strong again. Thanks all.

Sent from my iPhone 5 using Jeepz

 

[Grand.paneedshelp]

Steelheadz is there anyway you could help pointing me in the right direction to get this for the ECM? I need a wiring diagram for part #0514152aa 1998 Grand Jeep Cherokee. Thank you.

 

[SteelHeadz]

Here is a Schematic diagram for a 5.2V8 98GC. That part number you posted is missing a digit. i was going to decode that part number to see what engine you have but with a missing digit its a no go.. I hope this diagram helps you.

 

[Grand.paneedshelp]

I apologize. Yes the part # is 050141252AA its a 4.0L I also have the VIN #. I guess it originally had part# 56044513AC and the new computer is part # 56041576AB. The jeep would just stall randomly. We foimd on YouTube a video where this guy pushed down on the harness connected to the ECU and it would want to die. My only concern is three computers in 3 years. Anything you recommmend checking or how to check the present computer for resistance? Thank you. My grandmother really appreciates getting this thing out of their driveway and working again. Lol

 

[zitheran]

Just wanted to know if g106 and g107 from the diagram from the first post are just Chassie grounds?

 

[paradineai]

I have a (sort of) specific issue.
My jeep is a 1998 Grand Cherokee Limited (laredo with several limited features), 4.0L i6 and selec-track 4x4.

The black wire harness on the back of my alternator gets really hot.
As it heats up the total amps that my alternator put out drops.

When not using ANYTHING (other than headlights) it keeps a 13.75V on the battery.
However if I turn on something (radio, heater, fog lights, etc) the voltage starts going down to around 8.95V and hovers there with dim lights.

I also have heated mirrors so if I use the rear defrost they come on too. I want to separate these and put on another switch so I can use without rear window and also use the rear unit with mirrors. How can I do this quickly and easily?

Last is that my info display (lower unit) shows all 4 tires lighted even when in 2x4 mode and shows low mode even when in part-time high. Is this supposed to be like this or do I need to fix something else?

 

[Nysenarath]

I had the same issue the 98 Jeep Grand Cherokee was sitting for some time and did not have the time to get to it, I got it going after a couple of days ago. Here are the steps I went thru.
1) charged the battery to read above 12.6v, checked the voltage across the terminal while running, voltage was dropping below 12v , it should read above 13.5v
2) checked the wires that come out from the alternator, there are four
a) green, green with brown and a black ground wire that come out from the black box or what Chrysler call in the schematic "generator"
b) green and green/brown strip wires go to the PCM
c)at the top of the alternator there is a red (I think it's a gaug 4 wire) that goes and connects outside the fuse box next to the batters, this is the fuseable link, 1/2 red the other 1/2 green. Then there is another thick G4 red wire that connect to the fusable link outside fuse box that goes to the positive terminal.

 

[Nysenarath]

3) do a resistance check check on fusable link(thick red wire from fuse box to alternator terminal, then the other red wire from out side the fuse box to positive battery positive terminal
4) check the black box terminals green and green/brown resistance (to harness connector) this is where I had the problem, cold solder joint inside the black box or the so called the "generator"
5) cut the black box off and waited the two green wires to the alternator terminals and did a separate ground wire from alternator to body ground, that was it now the alternator charges the battery

 

[k-2]

I saw something I am not sure on - likely my reading comprehension.
I am not really following your issue, its confusing
BUT did you ground K20 DG wire ?
this will be 2 problems minimum - 1) a code, 2) constant and a overcharge

 

[Rooney]

Like I said, the main computer controls the alt. It gets corrosion inside and the drivers go bad. It's so common that it should have been a recall.

Replace the red word "it" in the quote to alternator. By being exact it helps those that are not so understanding of schematics or what drivers/diodes/rectifiers (all the same) are and (as stated by yourself earlier) where everything is taking place.

My car is a 2000 Cherokee of which has had problems that nobody has been able to figure out yet. They find this very topic of which they mostly understand, then every time I get my car back it's the same non charging issue every time. I figured it out myself this time after years of this and the battery temperature reader is too close to the fender. (ie. an open circuit sometimes)

So here is how to avoid this because as "carnuck" stated an overworked alternator over extended periods of time (more than a minute) will have problems with the drivers in the alternator. In my case this open circuit in the temperature reader is caused by having a battery that is too tall. It seems to have caused my drivers to go because after 15 volts alternator output were noted while driving, then 12 and then 9. This sensor gets bumped by the enforcement ridge in the hood when the battery is shifted too far of the left side of the holding tray and when closing the hood down. It's a style 2000 Cherokee 4.0 engine.

I'm not sure what battery these call for but neither do the mechanics most of the time so it's best to find out then check for damage before it's too expensive.

 

[Dave Allen]

As an aside. I had a similar problem with a Ford truck. As mentioned here it was the fusible link. About a $3 repair after a lot of head scratching. If you have a problem like this try this fix.

 

[Gennybro]

As an aside. I had a similar problem with a Ford truck. As mentioned here it was the fusible link. About a $3 repair after a lot of head scratching. If you have a problem like this try this fix.

that would be pretty cool.

 

[Gennybro]

just realized , we is discussing a 4 yr old issue, LOL, cheers !

 

[stryke23x]

Hi! this thread has been very helpful. I have a 1998 Cherokee XJ that stopped charging. The alternator was rebuilt but had tested ok prior anyway. We went and made sure all the grounds to the battery, frame, and the 4 by the PCM were cleaned up and reattached. I found that we are not getting power to the alternator field.

We have the following connector. The two center wires are green and green with a stripe. These connect to the field on the alternator. When turning the key it shows voltage for a split second and then goes away instantly. I am getting conflicting info on what is feeding this. One place says it is fed by the ASD relay. The relay seems to be working fine and it was swapped with another good relay with no change. One place says it is fed directly by the regulator in the PCM. That is my expectation. Another though stated it would be fed directly by the ignition. I expect that is less likely.

Does anyone have access to the wiring diagram that will show me where this green and green with a stripe go back to? I don't want to buy another PCM to try if there is more of a chance the issue is coming from somewhere else. Thank you for the help!



**Edit** I was able to find the PCM connector diagram. Wiring from B10 and C25 to the field terminals is good with no shorts. The PCM only sends power to the Field Source for that split second and stops though. Is there any where else I can trace this back to? Or is the PCM likely at fault? Everything else powered by the Fused ignition looks good. I get voltage at pin A2 for fused ignition switch and A22 has voltage.