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Discussion Starter · #1 ·
I have an 02 taurus with the vulcan. I am having the alternator intermittenly charge, and then not charge. I have replaced the battery along with a new alternator only to not solve the problem. I have tested each of the inputs to the alternator while the problem is occuring. Theres the 12V that comes from the battery, the ground, and the 8 volts that are there to excite the stator windings. Yet even when the battery voltage drops below 12V, it will not start charging. Sometimes it will kick back in right before the car dies, and sometimes, the car just dies from the lack of battery power. Does the PCM on the taurus have any type of control over the charging from the alternator, and could this be bad? I have checked all connections, fuses, wiggled wires. Everything. It seems after I disconnect the battery terminal, and then reconnect it, it will start charging again. This has been the only temporary fix. The car sometimes will run days without having any troubles.


Any help would be appreciated.

Thanks, Mark.
 

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My 95 Vuclan just had charging issues. The alternator died, so I replaced it with a new alternator from Pep Boys. The battery was dead too. So, I had a jumpstart and drove around for like 1 hour to fully charge the battery. After the first initial battery charge, how long did you drive it for?
 

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QUOTE (91BLOWNSC @ May 29 2010, 06:57 PM) index.php?act=findpost&pid=807727
I have an 02 taurus with the vulcan. I am having the alternator intermittenly charge, and then not charge. I have replaced the battery along with a new alternator only to not solve the problem. I have tested each of the inputs to the alternator while the problem is occuring. Theres the 12V that comes from the battery, the ground, and the 8 volts that are there to excite the stator windings. Yet even when the battery voltage drops below 12V, it will not start charging. Sometimes it will kick back in right before the car dies, and sometimes, the car just dies from the lack of battery power. Does the PCM on the taurus have any type of control over the charging from the alternator, and could this be bad? I have checked all connections, fuses, wiggled wires. Everything. It seems after I disconnect the battery terminal, and then reconnect it, it will start charging again. This has been the only temporary fix. The car sometimes will run days without having any troubles.


Any help would be appreciated.

Thanks, Mark.[/b]
On the 3G alternators, there is a single little wire that plugs into the alternator. This connector if it loses it clamp force,
can cause an intermittent connection and cause alternator issues. You can buy a replacement pigtail wire and replace it.

If you have a digital meter, when its not charging, first measure the battery voltage. Then the voltage out of the large lug
on the alternator. If its charging, it should be 14.5 or so. If its not charging, it will measure whatever the battery voltage is
which will be around 12.

If its not charging, see if you can measure the voltage on the single small wire by sticking the probe in the back side
of it while its still connected and report back with the value.

i got a quickie charge indicator at radio shack in the past. It plugs into the cigar lighter and has three LED's on it that will
give you a quick indication if its charging or not


http://www.genco1.com/tech_tip_details.cfm?id=72


bob
 

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Discussion Starter · #6 ·
QUOTE (soundu @ May 30 2010, 10:58 AM) index.php?act=findpost&pid=807885
QUOTE (91BLOWNSC @ May 29 2010, 06:57 PM) index.php?act=findpost&pid=807727
I have an 02 taurus with the vulcan. I am having the alternator intermittenly charge, and then not charge. I have replaced the battery along with a new alternator only to not solve the problem. I have tested each of the inputs to the alternator while the problem is occuring. Theres the 12V that comes from the battery, the ground, and the 8 volts that are there to excite the stator windings. Yet even when the battery voltage drops below 12V, it will not start charging. Sometimes it will kick back in right before the car dies, and sometimes, the car just dies from the lack of battery power. Does the PCM on the taurus have any type of control over the charging from the alternator, and could this be bad? I have checked all connections, fuses, wiggled wires. Everything. It seems after I disconnect the battery terminal, and then reconnect it, it will start charging again. This has been the only temporary fix. The car sometimes will run days without having any troubles.


Any help would be appreciated.

Thanks, Mark.[/b]
On the 3G alternators, there is a single little wire that plugs into the alternator. This connector if it loses it clamp force,
can cause an intermittent connection and cause alternator issues. You can buy a replacement pigtail wire and replace it.

If you have a digital meter, when its not charging, first measure the battery voltage. Then the voltage out of the large lug
on the alternator. If its charging, it should be 14.5 or so. If its not charging, it will measure whatever the battery voltage is
which will be around 12.

If its not charging, see if you can measure the voltage on the single small wire by sticking the probe in the back side
of it while its still connected and report back with the value.

i got a quickie charge indicator at radio shack in the past. It plugs into the cigar lighter and has three LED's on it that will
give you a quick indication if its charging or not


http://www.genco1.com/tech_tip_details.cfm?id=72


bob
[/b][/quote]


I do not have any single small wires that plug into my alternator. I have a set of 3 on a clip style connecter that securely snaps onto the alternator. I also have the main wire leading from the alternator that is screwed on. All connections are tight, clean, and secure. I have measure output though, and even driving it today is fine. Meaning, the voltage coming out of the alternator is the same as what its reading at the battery. However, this isn't ALWAYS the case, sometimes the reading at the battery is LOWER than what the output is at the alternator. I have checked the wires though and all of them seem fine.

Like I said, I keep a voltmeter in the car and monitor it realtime. And eventually it will just drop from 14.2ish to 12V and that charging has stopped. At that point I have to pull the car over and try to find the problem.


This is why I feel it may be a PCM problem. I just don't know its function in the whole process, or what each of the 3 small wires on that connecter do that lead into the alternator. KNowing that might help me out


Thanks!
Mark
 

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Discussion Starter · #7 ·
QUOTE (SHOZ123 @ May 30 2010, 01:00 PM) index.php?act=findpost&pid=807898
You should have 12V for the windings not 8V.[/b]

Well, like I said, I have 3 wires on a harness that clips into the alternator. I believe these wires come from the PCM. One reads the battery voltage (12V), one reads 0 (must be ground), and the final is around 8V. I assumed that was for the windings. If not, what is this voltage for and why is it 8 volts?
 

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The 8v one must go back to the battery warning light.
 

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QUOTE (91BLOWNSC @ May 30 2010, 02:01 PM) index.php?act=findpost&pid=807927
QUOTE (SHOZ123 @ May 30 2010, 01:00 PM) index.php?act=findpost&pid=807898
You should have 12V for the windings not 8V.[/b]

Well, like I said, I have 3 wires on a harness that clips into the alternator. I believe these wires come from the PCM. One reads the battery voltage (12V), one reads 0 (must be ground), and the final is around 8V. I assumed that was for the windings. If not, what is this voltage for and why is it 8 volts?
[/b][/quote]

Well i screwed up. you have a 6G alternator. they changed just past 2000 or so. It does not have the little switch wire.

you might find these links informative:

http://www.2carpros.com/forum/2002-ford-ta...t-vt416276.html

http://www.duboismarketing.com/pages/article.asp?id=18

bob
 
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