So my jeep had a trans problem whick ended up being an overcharging problem which baked the pcm (or ecm) and the tcm. So I brought it to jeep dealer and had them replaced. the alternator is still overcharging ON THE JEEP but NOT ON autozones tester. WHat the H*!! is going on the battery is new to.

its a 98 cherokee 4.0 automatic 4x4. 200000 miles exact

 

Well, it's good that the battery is new. But you won't get any higher of voltage from the battery alone. Are you sure they checked the alternator and not just the battery? The alternator can still be overcharging.

 

I took the atlernator off the jeep and had them bench test it 3 times. And no I do not know what they check because the retarded guy behind the counter doesn't even know h\what a spark plug is.

 

hmmm, I'd almost say you went to the parts store around the corner from me.

Did you take it back to the dealership where they replaced the parts for you?

 

Voltage regulator most likely... they aren't built in on later jeeps. They're built in to pcm. It is non serviceable. The only way to fix it is replace pcm or add an external.

 

"the alternator is still overcharging ON THE JEEP "

Don't depend on the dash gauge for any more than a reference measurement, check battery voltage with the engine running / engine off with a VOM. The PCM & TCM have their own internal regulators and operate at 5 vdc.

 

I know that but the frickn dealership won't tell me what they replaced. They just say they replaced the computer.

 

Don't tell me that, tell the dealership. They are dumber than a french fry, and are very rude. I highly recommend you NOT go there at all.

Center Garage in ceder lake, indiana

 

Well autozone is the first problem, new battery or old battery dont matter still can be bad check that out (just cause its new doesn't mean ****) Umm the stealership has to tell you what work was done ,so that is fishy begin you are saying that, they are bound by law so who's telling us a story here???

 

You need to tell them. It's your vehicle.

Now, something to take into consideration is that under (and I can't remember when they started doing this) the battery tray there is a little sensor. It's called a battery temperature sensor.

It's sole job is to communicate it's voltage reading to the PCM, which then adjusts the returned amount of voltage to the battery so that it doesn't get too much and start overheating.

If that little thing isn't operating properly (muddy, rusty, etc etc) and it's reading a colder temperature (less voltage sent to the PCM, means there is less heat and it therefore allows more voltage to return to the battery) then that COULD be your problem.

Check it out. You'll have to remove the battery, and then the tray underneath it. It's a little round piece of plastic (as looking at it from the battery tray) that has a sensor inside of it. It has wiring that runs down under to where your headlights are. You can disconnect it and replace it.

Ask them if they checked the battery temperature sensor. If they didn't do that, and just replaced the PCM, then they didn't followed outlined procedures. When dealers don't follow outlined procedures, they fix your problems for free. Ask for the checklist they followed, you need to see paperwork. They're supposed to fill out (check in the boxes) for procedures on anything they work on so they have documentation.

If they give you any flak about it, you need to call whoever is above that dealership. I don't know the phrase or what it actually is. I'm sure there's a regional/state level dealership that overlooks them. Sounds like you have a place that needs a good boot to the *** that hasn't been dealt because no one knows how things work out there.

ALSO, before you return there... I would actually take note of whether or not that BTS looks new, or old. If it looks old... find someone with a FSM, or AllData, and find out the testing procedure for it. It might be in a Haynes or Chilton, but I'm not sure. Test it to the T. You have to be careful because if you testing sensors wrong you can damage them. If you test it correctly and it's out of specs, then its at least half (if not ALL of your problem).

Also, I heard there was a TSB on wiring for alternators.. they needed a upgradeded wiring (bigger guage). I know from experience that with a smaller wire, they tend to get real fugg'n hot. And the hotter a wire is.. the more power it allows to flow through it. You could have both problems for all I know.

I do know that you can find out whether or not the TSB (if it applies) has been done to your vehicle by calling the dealership and giving them your VIN.