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Hello everyone,

I come to you for your wisdom and to see if anyone has run into this issue with their taurus. Let me give you brief history of my car.

Ford Taurus SEL DOHC, 249,000km on it

All my troubles start about more then a year ago,

First start with just my battery constantly getting killed and dying, Turned out my battery was shot. Replaced the battery, it was good for a bit the just died, then we traced the ac line that was corroding and leaking right on alternator and killing it. So i replaced that, my car began to work perfect. After winter comes along my car starts to begin to jolt while i was stopped at a light or anywhere, took it to my mechanic turns out my ac compressor was shot. I later replaced the ac compressor, after i put a new compressor in the car seemed ok, then the battery light came on again, turns out the alternator was bad, so we changed it with a new rebuild, been working since and then last night driving home a dreadful thing happened, the battery light came on. (and just an fyi when the battery light comes on, the ac is not being used)

Need help pleaseeeeeee
 

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have u installed anything that connects directly to battery? is it grounded properly?

i had this problem with one of my vehicles i had installed a new audio system and

i connect the power for the amp on the wrong positive post and killed my altenator

solution was to install power directly to battery and reset computer car has been

running awesome since
 

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Just to relate with an experience with a Mitsubishi, I had a bad alternator which I replaced with a rebuilt unit. The rebuilt one was defective. Then the 2nd rebuilt unit was good for about 6 months. Then it died. Then the next rebuilt one was good, for 2 months. Then I just bought a new OEM Denso one ($300 :eek:), and it lasted til I sold the car to a buddy. It's still going, and I sold it in 08'.

My advice, if the alternator keeps crapping out for no reason (now that the problems seem fixed), they getting an OEM new one.
 

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Check all of your fuses, I can't remember which one but if someone does please chime in - There is a fuse that is responsible for showing the alternator a "Differential Load" so it will charge, if that fuse is blown it will not charge the battery.
 

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Check fuses, do you have one of those dumbass systems in your car? Could be wired wrong. If all else fail,s go to the dealer, and get a new alternator. Some thngs you just shouldn't cheap out on.
 

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the alternator sense fuse.. it's like 7.5A...
I know mustangs have it.. dunno if the Taurus does.. but definetley look at the fuses just to eliminate it!
 

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Info.

Hello everyone,

I come to you for your wisdom and to see if anyone has run into this issue with their taurus. Let me give you brief history of my car.

Ford Taurus SEL DOHC, 249,000km on it

All my troubles start about more then a year ago,

First start with just my battery constantly getting killed and dying, Turned out my battery was shot. Replaced the battery, it was good for a bit the just died, then we traced the ac line that was corroding and leaking right on alternator and killing it. So i replaced that, my car began to work perfect. After winter comes along my car starts to begin to jolt while i was stopped at a light or anywhere, took it to my mechanic turns out my ac compressor was shot. I later replaced the ac compressor, after i put a new compressor in the car seemed ok, then the battery light came on again, turns out the alternator was bad, so we changed it with a new rebuild, been working since and then last night driving home a dreadful thing happened, the battery light came on. (and just an fyi when the battery light comes on, the ac is not being used)

Need help pleaseeeeeee
One more info you might not know:

The Powertrain Control Module (PCM) - Controlled charging system provides many additional benefits over the current Integral Generator Regulator system. The first benefit is improved battery life. In an integral generator regulator system, the regulator set point is established by a temperature sensor in the regulator which estimates battery temperature. Field data has shown this approach lacks accuracy. With a PCM-Controlled generator, the regulator voltage set point is determined by the PCM and communicated to the regulator via the generator communication line. The PCM will use a calibratable algorithm to estimate battery temperature. Improving battery temperature estimates will reduce battery damage caused by over- and undercharging.
The second benefit is improved engine performance. Whenever the PCM senses a Wide-Open Throttle (WOT) condition, the PCM will momentarily lower the regulator voltage set point. This reduces the torque load of the generator on the engine and improves acceleration. The PCM has a calibratable time limit on this reduced voltage feature. This is to prevent the generator output from being cut back for an extended WOT period, which could cause battery discharge.
The third benefit is improved idle stability. In response to the PCM's generator communication signal, the regulator uses a generator monitor signal to provide feedback to the PCM. The generator monitor signal provides the PCM with charging system information. Specifically, it lets the PCM know when the charging system receives a transient electrical load which would normally affect idle stability. Because the PCM can anticipate additional loads, actions can be taken to minimize idle sag. The PCM can choose to either reduce the regulator set point or increase engine idle speed, both of which are calibratable features. In order to establish whether the regulator is accurately maintaining the desired voltage set point, the regulator uses a charging system voltage line to sense battery voltage at the rear power distribution box.
The fourth benefit is reduced cranking efforts. The PCM can reduce the mechanical load on the starter by initially commanding a low voltage set point. This may improve start times.
If the PCM detects a charging system error, it will broadcast a low voltage telltale (ON) command which tells the cluster to light the charge indicator. The charge indicator will be illuminated if the PCM fails to see a signal on the generator monitor line for a time period greater than 500 milliseconds . This telltale command will also be used to indicate over-voltage conditions detected by the PCM controlled generator.
Each time the ignition switch is cycled to the run position, the cluster will initiate a bulb check by illuminating the charge indicator. It is the PCM's responsibility to issue a low voltage telltale (OFF) command if the charging system is functioning properly. This message should be sent during Network Initialization in the voluntary phase (250 milliseconds to 450 milliseconds after the ignition switch is cycled to the run position). If a low voltage telltale (OFF) command is not received by the cluster, the cluster will continue to light the charge light indefinitely.
------------------------------------

So this does not apply to older cars, but at lease Gen4 With DOHC.

So, an overcharge can set the light, even brief one. Overcharge (over voltage) can be caused by a bad connection from the battery to the fuse box. The Alt charges from the Alt to the fuse box, and then to the battery. Any weak connection there can cause a higher voltage than expected.

Just something to think about.

-chart-
 

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Mega

Ye old mega fuse!
My diagram shows, for DOHC there is a 10A fuse that goes to the regulator, wire OG/YE after the 10A fuse. If the 175A goes, then no power to the 10A. The regulator also gets LB/RD and GY/YE from the PCM.

The Vulcan is different.

If that helps.

-chart-
 

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Just a thought, but my 05 Sable was giving similar problems for almost a year. Changed battery, starter assembly, relays, etc., but a new ignition switch solved the problem. Easy to replace and relatively cheap at around $20 or so. Couple of bolts under the steering column, two more to get the box off the column and one to undo the cable connector from the switch. One of those shouldda done that first kinda things.
 
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