93 Jeep Cherokee XJ Code 41

Ok guys this is whats going on..First thing is check engine light would come on every once in awhile and along with that the voltage guage would drop to 9-10 range....Then it happened more frequently...shutting the engine and restarting would sometime cause the check engine light to go off and voltage guage would read normal....So I am thinking the alternator is bad,,,,so I got a new one from Autozone and replaced it and the check engine light was still on as soon as I started my Jeep...So then Someone told me to do the Key On Key Off and get the codes....I got Code 41 which is "[FONT=&quot]Charging system circuit-output driver stage for generator field does not respond properly to the voltage regulator control signal" Ok,,,,so what does that mean? I have search the web, but can't find out what needs to be replaced if I get this code....Any help apprecaited....
Jim
South Carolina

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Sometimes the computer has to see the change a few times before it dismisses the code from the ecu. So after you have installed your replacement alternator are your voltages ok ? I would drive the car normally for a few days and see i it goes away on its own.

pete

Update,
I checked the voltage with a meter. down to 11.....I bought a new computer from autozone thinking it has to be the voltage regulator,,,,no dice....Still does the same thing.....If i leave the vehicle alone for a day and start it, it charges at 14.5 for about 5 minutes and then check engine light and volts start to go down.....So I read that someone changed out the ASD relay,,,,so I did too,,,,no dice again.....same thing again,,when I started it cold,,,,it charges fine for about 5 to 10 minutes,,,then the volts drop to about 11 and the check engine light comes on,,and i get the code 41 again.....This is my first Jeep and I have owned it for about two weeks,,and as soon as I get it fixed,,can anyone say "FOR SALE"....oh yea,,,btw, thanks for the reply Jeepsrock...

Jim
South Carolina
RockClimber 4 Life

Update.
Today I bought a new battery. Installed it...Started it for the first time since yesterday.....running fine,,,no check engine light...alternator charging at over 14 volts.....good deal......but wait.....5 minutes passes...check engine light,,.....voltage gauge drops.....voltage meter showing the volts start to drop....13.....12.25.....and hangs about there....
Dang Jeep

Jim Smith
South Carolina
RockClimber 4 Life

jimsmith29841 said:

Update.
Today I bought a new battery. Installed it...Started it for the first time since yesterday.....running fine,,,no check engine light...alternator charging at over 14 volts.....good deal......but wait.....5 minutes passes...check engine light,,.....voltage gauge drops.....voltage meter showing the volts start to drop....13.....12.25.....and hangs about there....
Dang Jeep

Jim Smith
South Carolina
RockClimber 4 Life

Click to expand...

Darn Jeep? Your just a bad guesser. Is you fan belt loose?

LOL,,,,yep it seems I am a bad guesser,,,,but no my fan belt is not loose,,,,one of the first things I checked.....
Tomorrow I am going to pull the alternator off again,,,have it checked and recheck all my connections again,,,,,I will post what happens....
Thanks

It has something to do with the little black box mounted on the back of the alternator. The code should be for the alternator field control circuit. Mine was doing the same thing when I bought it and it turned out to be a wire that leads into the box was cut. Track down all of the wires and make sure they are all good then check the harness right there under the fuse box the wires run into that. It is a very frustrating situation and I learned the hard way after buying 2 batteries and swapping out the alternator 3 times. That box is not available either, it is part of the engine harness so hopefully one of my suggestions will be able to help you. Good luck!!

Solution: Replace the alternator bracket with one from a 1988 model and throw in a Delco one-wire alt from Quick Start......no more problems,,,,I am on my second jeep that gave me the same 41 fault code....so I fixed it this way.