cherokee00

i have a 2000 cherokee with the i6.. im having a problem with my charging system just looking to confirm some things. every few days the alternator would stop charging.. so id take the negative wires off the terminal, clean them with a wire brush and then it'd be fine.. well now its starting to do it more often, so today i took all the wires off, cleaned every end and put it all back together. once again it was fine... then i went to take it to the store and it stopped charging again. now if im not mistaken the voltage from the alternator is regulated through the ecu (voltage regulator). im beginning to think i need a new ecu and all ive been doing is resetting it by disconnecting the negative terminal. so my question is does this sound about right? or has anyone else had this problem? thanks

cherokee00

anyone?

95THORxj

could be ecu. but id check all grounds and connections before
condeming the ecu. take alt off & have a/z check it. if putting out,
then go from there.

cherokee00

well i work at advance so i pulled it out and checked it there lol no a/z for me.. and it tested fine.. so today i took all the cables off and cleaned them, all the ground wires, everything, then i started it and let it run for about 5 or 10 minutes and it was fine.. turned it off, went inside ate dinner, and went to take it to the store and about halfway home the volts dropped to about 9 and im back to square one!

95THORxj

well then id have to say get a used ecu at jy. sorry.

cherokee00

i just wanted to make sure that im not gonna be wasting my money, seeing if anyone else has had this problem of might know of something im missing, as im kinda new to the whole jeep thing..

95THORxj

with everything uve done thats the last thing to replace,
i deff wouldnt buy one at a advance. haha
u prob could get a good deal on it though.

cherokee00

yea i could probably get a GREAT deal on one.. but im gonna try a jy first and make sure thats the problem.. in my eyes it has to be.. ive tried everything else and it keeps happening.. i just dont see why the time inbetween it happening is changing.. sometimes itll work for 24 hours.. sometimes it doesnt work att all.. hmm

95THORxj

gotta be an internal short that takes that time to show up??
thats the only thing i can think of??
good luck and let me know the outcome.

cherokee00

ok so i have come to the conclusion i need an ecm.. after cleaning all the wiring and reconnecting everything i was still having the same problem, so today while at work i changed my negative terminal hooked everything up and it seemed to be fine while i let it idle for about 10 minutes. after work i was letting it idle and it was charging at 14 volts, it then dropped to about 12. so i shut it off, took the new negative cable off, let it sit for about 5-10 minutes, reconnected it and it was back to 14 volts. i then drove 30 minutes home and it ran fine the whole way. i turned a corner and put it to the wood and the voltage dropped and it started to die.. im thinking the ecm is shot? any input would be greatly appreciated!! thanks in advance..

dham99

it started to die right away? it should at least run off the battery for a while before you notice the lights dimmer and stuttering issues from fuel/air management problems (since they have no power).

Ive been troubleshooting a new alternator but NO charge for weeks now. Dont know if it helps at all, Im narrowing it down to a single wire.

Heres my link to the thread...
https://www.cherokeeforum.com/f2/new...ge-pics-62755/

cherokee00

well what happens is it will run for awhile at 14 volts.. then drop to about 12, then nothing and itll die.. but what ive been doing is, when i notice it starting to drop, i pull over beore it has time to kill the battery, disconnect the terminal, let it sit for a few, clean the wire, reconnect, and its back up to 14.. i think all ive been doing is resetting the ecm by disconnecting the terminal, then once its reconnected it ok for a little then it dies again.. and its still doing it after i replaced the negative cable...

jeff2285

your ECM doesnt control the altenator in a old jeep lol
you need a new altenator becuase your voltage regulator it tut fukeeeeed
and the voltage regulator is part of your altenator not your computer

cherokee00

if the voltage regulator was fu*ked then why would it start working after disconnecting the negative terminal for a couple minutes? ive pulled the alternator out and put it on a bench test and its testing fine...

jeff2285

go buy a new altenator and it will work fine. there is a coil winding opening up when hot.