ECU/Alternator Problem
08-11-2007, 04:29 PM
#11
Guest
Posts: n/a
Re: ECU/Alternator Problem
Thank you for all the suggestions.
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
08-11-2007, 04:29 PM
#12
Guest
Posts: n/a
Re: ECU/Alternator Problem
Thank you for all the suggestions.
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
08-11-2007, 04:29 PM
#13
Guest
Posts: n/a
Re: ECU/Alternator Problem
Thank you for all the suggestions.
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
Still trying to figure this one out.
Last weekend, I probed the battery cables from the battery to the
alternator, to ground, etc... checking for voltage drops. They
appeared to check out ok, but I checked and cleaned ground connections
all over the engine compartment anyway.
Next, I bought a used engine control unit at the junk yard for $25.
After swapping them out, the problem still occurred.
My next thought was the alternator, so I swapped it out earlier this
week. Here comes the head scratcher. The problem seemed to greatly
decrease in frequency. However, instead of overcharging at 19 volts
the needle will only breifly sweep up to 15 or 16 volts. Even more
strange is that it only does it while accelerating through fairly
sharp corners or turns. In the past few days, it has done this
probably 3 or 4 times, but only swept high enough once to click on the
ABS light and cause the shifting problems with the computer I
described earlier.
I had replaced a dead battery a few weeks before this problem cropped
up, so I thought perhaps the new battery had some intermittent
shorting issue. Replaced it this morning with no apparent impact to
the problem.
So to recap, I have ruled out the voltage regulator in the computer,
the battery, and maybe the alternator (improved the problem, but
didn't eliminate it).
Anyone have any advice or ideas?!
08-11-2007, 05:58 PM
#14
Guest
Posts: n/a
Re: ECU/Alternator Problem
ds1234567890@hotmail.com wrote:
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
08-11-2007, 05:58 PM
#15
Guest
Posts: n/a
Re: ECU/Alternator Problem
ds1234567890@hotmail.com wrote:
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
08-11-2007, 05:58 PM
#16
Guest
Posts: n/a
Re: ECU/Alternator Problem
ds1234567890@hotmail.com wrote:
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
08-11-2007, 05:58 PM
#17
Guest
Posts: n/a
Re: ECU/Alternator Problem
ds1234567890@hotmail.com wrote:
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
> Thank you for all the suggestions.
>
> Still trying to figure this one out.
>
> Last weekend, I probed the battery cables from the battery to the
> alternator, to ground, etc... checking for voltage drops. They
> appeared to check out ok, but I checked and cleaned ground connections
> all over the engine compartment anyway.
>
> Next, I bought a used engine control unit at the junk yard for $25.
> After swapping them out, the problem still occurred.
>
> My next thought was the alternator, so I swapped it out earlier this
> week. Here comes the head scratcher. The problem seemed to greatly
> decrease in frequency. However, instead of overcharging at 19 volts
> the needle will only breifly sweep up to 15 or 16 volts. Even more
> strange is that it only does it while accelerating through fairly
> sharp corners or turns. In the past few days, it has done this
> probably 3 or 4 times, but only swept high enough once to click on the
> ABS light and cause the shifting problems with the computer I
> described earlier.
>
> I had replaced a dead battery a few weeks before this problem cropped
> up, so I thought perhaps the new battery had some intermittent
> shorting issue. Replaced it this morning with no apparent impact to
> the problem.
>
> So to recap, I have ruled out the voltage regulator in the computer,
> the battery, and maybe the alternator (improved the problem, but
> didn't eliminate it).
>
> Anyone have any advice or ideas?!
>
Ground strap across an engine mount to the frame bad or a bad body ground?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's - Gone to the rust pile...
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
08-12-2007, 02:14 PM
#18
Guest
Posts: n/a
Re: ECU/Alternator Problem
On Aug 11, 3:58 pm, Mike Romain <roma...@sympatico.ca> wrote:
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?
08-12-2007, 02:14 PM
#19
Guest
Posts: n/a
Re: ECU/Alternator Problem
On Aug 11, 3:58 pm, Mike Romain <roma...@sympatico.ca> wrote:
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?
08-12-2007, 02:14 PM
#20
Guest
Posts: n/a
Re: ECU/Alternator Problem
On Aug 11, 3:58 pm, Mike Romain <roma...@sympatico.ca> wrote:
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?
> ds1234567...@hotmail.com wrote:
> > Thank you for all the suggestions.
>
> > Still trying to figure this one out.
>
> > Last weekend, I probed the battery cables from the battery to the
> > alternator, to ground, etc... checking for voltage drops. They
> > appeared to check out ok, but I checked and cleaned ground connections
> > all over the engine compartment anyway.
>
> > Next, I bought a used engine control unit at the junk yard for $25.
> > After swapping them out, the problem still occurred.
>
> > My next thought was the alternator, so I swapped it out earlier this
> > week. Here comes the head scratcher. The problem seemed to greatly
> > decrease in frequency. However, instead of overcharging at 19 volts
> > the needle will only breifly sweep up to 15 or 16 volts. Even more
> > strange is that it only does it while accelerating through fairly
> > sharp corners or turns. In the past few days, it has done this
> > probably 3 or 4 times, but only swept high enough once to click on the
> > ABS light and cause the shifting problems with the computer I
> > described earlier.
>
> > I had replaced a dead battery a few weeks before this problem cropped
> > up, so I thought perhaps the new battery had some intermittent
> > shorting issue. Replaced it this morning with no apparent impact to
> > the problem.
>
> > So to recap, I have ruled out the voltage regulator in the computer,
> > the battery, and maybe the alternator (improved the problem, but
> > didn't eliminate it).
>
> > Anyone have any advice or ideas?!
>
> Ground strap across an engine mount to the frame bad or a bad body ground?
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's - Gone to the rust pile...
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06http://www.imagestation.com/album/pictures.html?id=2115147590
> (More Off Road album links at bottom of the view page)
Found one body ground yesterday that I missed, so I cleaned it....have
to wait and see if it works. Do you think the field driver that
attaches to the alternator could be bad? What should the voltages be
on the two connections?