NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old February 17th, 2019, 16:45
Club31XJ's Avatar
Club31XJ Club31XJ is offline
NAXJA Forum User
 
Join Date: Mar 2017
Location: Canyon Lake
Posts: 27
As if things couldnít get worse

Ok guys so Iíve posted a couple different threads here pertaining to my 1991 4.0 jeep xj. My first issue was not getting spark. Found that the problem was a faulty pcm. During the process though I replaced a boat load of part. Starter, alternator, battery, spark plugs and wires, coil, distributor, and also pcm. Finally got it all started and was running fine for about 40 miles. Then noticed a check engine light came one and my battery voltage was way low. The check codes it threw were 34,41,21 and 62. I figured out the 34 code (map sensors vavcuum hose was clogged. 62 says itís not reading my odometer and the 41 is the alternator is not charging the battery but as I stated before itís brand new. So I have no idea what my problem is. The pcm is an A1 Cardone which I ordered online. I didnít have the original serial sticker number from the old one because there was no sticker on it. So I put in online the type of vehicle I had assuming it would be the correct one. Everything was working fine except now Iím getting this 41 code and the alternator is not charging. What in the holy hell is going on?


Sent from my iPhone using Tapatalk
Reply With Quote
  #2  
Old February 17th, 2019, 17:00
IslanderOffRoad's Avatar
IslanderOffRoad IslanderOffRoad is online now
NAXJA Forum Addict
 
Join Date: Apr 2006
Location: Houston, Tx
Posts: 8,793
Re: As if things couldnít get worse

How tight is the belt?
__________________
John V.
RRC VP
DAL
01 XJ Sport 2 door 5spd/4WD- 4" lift, Rubi wheels/tires JCR bumpers/sliders, armor, Rubi 44, Ford 8.8, 4.56's, ARBs.
Reply With Quote
  #3  
Old February 17th, 2019, 17:10
Green Mesa XJ's Avatar
Green Mesa XJ Green Mesa XJ is offline
NAXJA Forum User
 
Join Date: Aug 2004
Location: Pensacola, FL
Posts: 1,159
As if things couldnít get worse

If the belt and wires to the alt are good, then the pcm is bad. Alternator voltage is controlled through the pcm,

Of course the alternator could be faulty, you could have it tested, if the belts and wires are good. But if itís good and everything else is as well then the pcm is bad.

A1 used to be a better name, but they easily could have sold a faulty pcm.


Sent from my iPhone using Tapatalk Pro
Reply With Quote
  #4  
Old February 17th, 2019, 20:06
Scrubber3 Scrubber3 is offline
NAXJA Forum User
 
Join Date: Feb 2019
Location: North Carolina
Posts: 24
As if things couldnít get worse

Test battery. Check belt tension. Test alternator. I've seen brand new alternators give up the ghost after a few miles on them.
Reply With Quote
  #5  
Old February 17th, 2019, 20:39
POSrenix's Avatar
POSrenix POSrenix is offline
NAXJA Forum User
 
Join Date: Jan 2019
Location: simi valley
Posts: 30
Re: As if things couldnít get worse

you could rig alt with an external voltage regulator early 80 dodge style
Reply With Quote
  #6  
Old February 18th, 2019, 08:11
Anak's Avatar
Anak Anak is offline
Stranger
 
Join Date: Sep 2013
Location: In a strange land
Posts: 2,968
Re: As if things couldnít get worse

There are kits for that: https://alternatorparts.com/external...nator-kit.html

That is just one example. The information at the bottom of the page is worth noting.
__________________
Project "Scope Creep": 1996 4wd 4.0L, AX15
....

Baby it's cold outside.
Reply With Quote
  #7  
Old February 18th, 2019, 10:43
POSrenix's Avatar
POSrenix POSrenix is offline
NAXJA Forum User
 
Join Date: Jan 2019
Location: simi valley
Posts: 30
Re: As if things couldnít get worse

in the kit i see the field replacement module used to trick the computer from throwing a code is this a resistor? i ordered mine from rock auto with wire harness for under 20$
Reply With Quote
  #8  
Old February 18th, 2019, 10:46
Club31XJ's Avatar
Club31XJ Club31XJ is offline
NAXJA Forum User
 
Join Date: Mar 2017
Location: Canyon Lake
Posts: 27
As if things couldnít get worse

I thought that maybe some important information of something that I have found out is that when the engine is cold the alternator seems to be working but as soon as I get up to operating temperature it throws the code 41 and the alternator stops working. I was going to try and run some test with the ohm meter to see if there might be a short in the circuit somewhere.


Sent from my iPhone using Tapatalk
Reply With Quote
  #9  
Old February 19th, 2019, 14:19
Rob Mayercik's Avatar
Rob Mayercik Rob Mayercik is offline
NAXJA Member #920
 
Join Date: Jun 2002
Location: NJ, U.S.A.
Posts: 2,148
Re: As if things couldnít get worse

Slightly loose connection that's opening up as things warm up and expand?
__________________
1992 Cherokee Laredo: "A wonderful balance of grace and rust"
1984 Dodge Omni
2002 Volkswagen Jetta GLS TDI
Reply With Quote
  #10  
Old February 19th, 2019, 15:46
Agreen Agreen is offline
NAXJA Forum User
 
Join Date: Nov 2016
Location: Charleston
Posts: 24
Re: As if things couldnít get worse

Just saying that the alternator is new doesn't mean that it's charging. Have you verified the battery voltage? It should read about 13.2 at idle. If it's not reading that, it could be as simple as a bad ground wire.
Reply With Quote
  #11  
Old February 21st, 2019, 21:06
lawsoncl lawsoncl is offline
NAXJA Forum User
 
Join Date: Jan 2006
Location: North Idaho
Posts: 4,892
Re: As if things couldnít get worse

Quote:
Originally Posted by POSrenix View Post
in the kit i see the field replacement module used to trick the computer from throwing a code is this a resistor? i ordered mine from rock auto with wire harness for under 20$

Looks like it. Probably just to put a load across the lines from the computer so it doesn't think it's an open or shorted circuit. Although, I'd suggest that if it works to avoid the trouble code, then the PCM is likely to be able to control the alternator field coil by itself and you don't need an external regulator. $20 for a $2 resistor seems a bit high on the markup.


Have you measured the voltage across the field terminals when it's failing to charge? That'll tell you if the problem is the alternator or the pcm/wiring. Disconnecting the wire from the computer and putting full voltage across the field coil should also tell you if its the alternator not charging as well.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
2014 keeps getting worse and worse eflores Colorado Chapter 87 April 17th, 2014 21:54
And Just When You Thought It Couldn't Get Worse...It Does! joe_peters Political Discussion Zone 18 March 3rd, 2010 12:47
Just when things couldnt get worse. . . XJCruiser North Atlantic Chapter 48 January 7th, 2009 17:01
this week just gets worse and worse fuelfox4949 Modified Tech Discussion 3 November 12th, 2008 09:08
adjusted gear box, made things worse! need help fast! dfreeman616 OEM Tech Discussion 12 August 6th, 2005 08:21


All times are GMT -7. The time now is 06:30.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014