Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here XJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.

Voltage Drops at Stop

Thread Tools
 
Search this Thread
 
Old 12-30-2010, 08:55 AM
  #1  
Seasoned Member
Thread Starter
 
Screwd up 6's Avatar
 
Join Date: Nov 2010
Location: Spring, TX
Posts: 469
Likes: 0
Received 0 Likes on 0 Posts
Year: 1994
Model: Cherokee
Engine: 4.0
Default Voltage Drops at Stop

I have been reading online and searching and have found similar threads about it, but some guys seem to run in circles on this issue.

When Im driving, my voltage gauge shows about 12-14 volts. When I come to a stop the gauge drops to 9. The lights dont dim, the jeep has no problems running or anything. I figure it might be the alternator, but am wondering could this be the voltage regulator?
Old 12-30-2010, 09:04 AM
  #2  
"CF Moderator"
 
TrekkerJmm's Avatar
 
Join Date: Sep 2008
Location: N.J. Shore Area
Posts: 3,045
Likes: 0
Received 2 Likes on 2 Posts
Year: 1994
Model: Cherokee
Engine: l6 HO
Default

Originally Posted by Screwd up 6
I have been reading online and searching and have found similar threads about it, but some guys seem to run in circles on this issue.

When Im driving, my voltage gauge shows about 12-14 volts. When I come to a stop the gauge drops to 9. The lights dont dim, the jeep has no problems running or anything. I figure it might be the alternator, but am wondering could this be the voltage regulator?
At what RPM does it show charging? and what RPM does the jeep idle at...Tj
Old 12-30-2010, 10:13 AM
  #3  
Seasoned Member
Thread Starter
 
Screwd up 6's Avatar
 
Join Date: Nov 2010
Location: Spring, TX
Posts: 469
Likes: 0
Received 0 Likes on 0 Posts
Year: 1994
Model: Cherokee
Engine: 4.0
Default

Originally Posted by TrekkerJmm
At what RPM does it show charging? and what RPM does the jeep idle at...Tj
I will have to look at that. I know it idles smoothly with no hesitation or struggle. The voltage starts to go up as soon as i start to give it gas.
Old 01-07-2011, 09:03 PM
  #4  
Member
 
Grasshoppa's Avatar
 
Join Date: May 2010
Location: Milton, Fl
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L High Output
Default

hey buddy i was wondering if you figured this out? i was doing a search and came across your thread. i have the same syptoms but all my lights, heater and radio light dim until i give it gas...my buddy thinks its alternator. JW if you had an outcome?
Old 01-07-2011, 11:44 PM
  #5  
Member
 
sheepdog's Avatar
 
Join Date: Feb 2010
Location: South West Wyoming
Posts: 224
Likes: 0
Received 0 Likes on 0 Posts
Year: 1993
Model: Cherokee
Engine: I-6 h.o.
Default

you can take it to most parts shops and they will throw a tester on there and tell you if your alternator is bad, for free, and if it is bad, problem solved replace it, if not, i dont know lol do what any sensable jeeper would do, start throwing random junk yard parts at it until it is fixed lol
Old 01-08-2011, 06:01 AM
  #6  
Member
 
Grasshoppa's Avatar
 
Join Date: May 2010
Location: Milton, Fl
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L High Output
Default

thats the thing for an american living in the UK. we have to pay the exchange rate...even at junk yards. another wonderful plus is that they dont have a bad a$$ autozone or nothing like that over here to test an alternator. im damn sure i aint payin for a 200 dollar alternator if thats not the problem. lol. **** sucks but what can you do when uncle sam owns your life...lol
Old 01-08-2011, 06:40 AM
  #7  
CF Veteran
 
SeriousOffroad's Avatar
 
Join Date: Apr 2008
Posts: 13,952
Likes: 0
Received 15 Likes on 13 Posts
Model: Cherokee
Default

Got a hobby shop on base?
Old 01-08-2011, 07:34 AM
  #8  
CF Veteran
 
hitalonit's Avatar
 
Join Date: Nov 2009
Location: St. Clair Shores, MI
Posts: 1,103
Likes: 0
Received 0 Likes on 0 Posts
Year: 1999
Model: Cherokee
Engine: Inline 6
Default

i use to have that problem with my eagle talon... the alternator couldnt handle the load... but i had led's inside,subs,and under glow...do you have anything extra that could be wieghing it down ?? lights ? i upgraded to a bigger alt and had no more problems...
Old 01-08-2011, 09:25 AM
  #9  
Member
 
Grasshoppa's Avatar
 
Join Date: May 2010
Location: Milton, Fl
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0L High Output
Default

yea. i we have a hobby shop. cant remember if they had a tester though. id imagine they would...didnt even think about it...lol...i dont have any mods to weigh it down. just stock. aftermarket CD player, thats it. use to have a sub and all that but took it out.
Old 01-08-2011, 10:39 AM
  #10  
Senior Member
 
Coach's Avatar
 
Join Date: Jan 2010
Location: Lyons, Oregon
Posts: 536
Likes: 0
Received 0 Likes on 0 Posts
Year: 1991
Model: Cherokee
Engine: 4.0 HO
Default

voltage regulator is supposed to keep the voltage faily constant, it's part of the alternator. if the lights arent dimming i would check the voltage at the battery when idleing if it's below 12, replace the alt.
Old 01-08-2011, 11:46 AM
  #11  
CF Veteran
 
SeriousOffroad's Avatar
 
Join Date: Apr 2008
Posts: 13,952
Likes: 0
Received 15 Likes on 13 Posts
Model: Cherokee
Default

Nope, not in an XJ. The regulator is in the pcm.
Old 01-08-2011, 11:51 AM
  #12  
Senior Member
 
KTMrider's Avatar
 
Join Date: Sep 2008
Location: MD
Posts: 504
Likes: 0
Received 0 Likes on 0 Posts
Year: 2000
Model: Cherokee
Engine: 4.0
Default

Try this. When your car is barely able to idle open up the fuse box and tap the "ASD" relay. Thats what caused an issue on mine. If that fixes the issue, it's a 15$ relay.
Old 01-08-2011, 01:08 PM
  #13  
Member
 
billfrank85's Avatar
 
Join Date: Sep 2010
Location: Grand Rapids, MI
Posts: 234
Likes: 0
Received 1 Like on 1 Post
Year: 1994
Model: Cherokee
Engine: 4.0
Default

This same thing was happened to me at red lights. I would come to a stop, my engine would start running rough and my voltage would drop and sometimes it would die...I replaced the IAC sensor and it fixed the problem.
Old 01-08-2011, 03:45 PM
  #14  
Newbie
 
Xj7054's Avatar
 
Join Date: Jan 2011
Location: Ny
Posts: 25
Likes: 0
Received 0 Likes on 0 Posts
Year: 1998
Model: Cherokee
Engine: 4.0
Default

I had the same problem in my rodeo but never my jeep. The altenater wasn't putting out enough of a charge at idle. Went through 3 alternators in less than a year before I realized that pepboys parts suck. Hasn't happened since.
Old 01-08-2011, 04:30 PM
  #15  
Senior Member
 
Coach's Avatar
 
Join Date: Jan 2010
Location: Lyons, Oregon
Posts: 536
Likes: 0
Received 0 Likes on 0 Posts
Year: 1991
Model: Cherokee
Engine: 4.0 HO
Default

Originally Posted by FrankZ
Nope, not in an XJ. The regulator is in the pcm.
Wow, I didn't know that, Thanks!


Quick Reply: Voltage Drops at Stop



All times are GMT -5. The time now is 11:49 AM.