2002 Limited Charging System Issue

[drfood55]

I own a 2002 Jeep Liberty Limited and am having a heck of a time diagnosing a charging system issue. Seems like one piece of the puzzle leads to another. I love my Libby and want to keep it a while longer, but this is driving me crazy.

Symptoms--

• Battery light on dash on currently
• No check engine light
• No faults on ODBII reader
• Voltage on battery 12.55 when ignition off
• Voltage on battery 11.65 when engine running

Things done so far

• New battery
• New radiator cooling fan relay
• New battery temperature sensor
• Alternator checked at O'Reilly and AutoZone and alternator shop
• Checked fusible link between alternator and battery

Dealer wants to charge me $145 just to test the PCM and give a diagnosis.

I've read more comments on forums that I could possibly digest. I've deduced it has to be the voltage regulator, hence I am suspecting the PCM needs to be replaced.

I am more than willing to replace the PCM if needed, but so far I cannot find a reputable vendor on-line. All of the one's I have spoken to have HORRIBLE ratings from consumers.

Right now the Liberty is sitting in the driveway and I am commuting on my motorcycle. So getting to and from work is working.

Any and all suggestions are very much welcome. If you know of a good auto electrical expert in Houston I'm open to hearing about that. And if you have a recommendation on a source for a PCM that is welcome as well.

Thanks ahead of time.

Darrell

 

[CactusJacked]

I would replace the PCM only as a last resort.
It's not an uncommon issue, they make an external regulator kit: ERCKFRM Combo - Heavy Duty Chrysler, Dodge, Jeep External Voltage Regulator Kit with Field Replacement Module

[YT]utXjxwPAcHk[/YT]

 

[TypeRx]

Are you sure the alternator is still okay? I thought the load tests at the parts shops don't work perfectly on our jeeps. I recently swapped my alternator (brand new nippondenso 136 amp for $84 shipped) and all is well....

Have you used a multimeter on the positive terminal on the alternator (and negative on chassis) while the engine is running?

Sent from my iPhone using Tapatalk

 

[renegade 04]

You could by a ford extra heavy duty voltage regulator like me and give it a try.
here are the steps
If you do decide to by a new ECM you may create new issues that you do not have rite now like engine problems.
first thing you will need is a spare alternator connector, I got mine from a junk yard.
here is a link for that
http://shop.advanceautoparts.com/p/...utm_campaign=27795&utm_content=120917&irgwc=1
Next you will need the voltage regulator connector.
http://shop.advanceautoparts.com/p/...utm_campaign=27795&utm_content=120917&irgwc=1
You will also need to get the voltage regulator.
http://www.ebay.com/itm/FORD-Extern...m3604de0434:m:mrIDXh1IYFoAQfWU_Qbg0Sg&vxp=mtr
Next you will want to run a ground from the alternator to the case of the voltage regulator.
Next run a wire from a switch ignition source like the radio to the terminal labeled I.
Next run a wire from the alternator positive lug to the terminal labeled A.
Next run a wire from the Black/white colored wire on the alternator connector to Ground.
Next run a wire from the Dark Green colored wire on the alternator connector to the terminal labeled F.
As a side not you will not need to use the Terminal labeled S.
Also note that you will have the battery light on, but there is a part called a field replacement module for that.
http://store.alternatorparts.com/frm-field-replacement-module.aspx
Also note that this is for a FORD voltage regulator not a Chrysler voltage regulator.
These are the steps to install a external voltage regulator, but I would use the extra heavy duty voltage regulator like the ones I found on ebay.
http://www.ebay.com/itm/FORD-Extern...m3604de0434:m:mrIDXh1IYFoAQfWU_Qbg0Sg&vxp=mtr
the part number for the extra heavy duty is transpo F540XHD
The full tread is http://www.jeepkj.com/forum/f202/external-regulator-59831/

 

[renegade 04]

Feel free to send me a PM if you have any more questions about hooking it up.

 

[JasonJ]

Voltage regulator, integral to the PCM. That's my thought as well.

You've been provided some very excellent options in the previous posts.. I would absolutely go one of those routes before I EVER replaced a PCM, especially in a Chrysler vehicle...