2000 Windstart Alternator Smart Charge 14.7v @start, 12.5v after 30 minutes

[MrCreosote]

I need to check recovery at the battery. It will take some time with the weather here.

[12Ounce]

Originally Posted by MrCreosote

12ounce,

If you have an earlier Windstar, you might just have a conventional charging circuit.

The SCS (Smart Charge System) has a 3-wire connector on the top of the alternator in the rear. These are 3 small signal wires.

If you have that, you are screwed.

.

.
The build date on my 3.8 is 1/99. The pub date on my electrical diagram book/shop manual is Aug 1998.

Both the diagram book, and "real world", show a rear clip-on connector on the alternator rear/top. 3 wire....OG/LB, RD/BK, VT. .. There is also the 12v YE/WH terminal ... and perhaps two other ground connections. Two of the three wires (RD/BK and VT) connect to PCM terminals.

In the diagram book, near the illustration for the alternator (which shows some simple renderings of diodes, windings, etc.) is this comment:
"Generating power to keep the battery fully charged and to operate the vehicle's electrical system. Output is variable and depends on speeds at which the generator rotor spins, as well as amount of current passing through the rotor winding. Current flow through the rotor is controlled by built-in regulator. Stator generates alternating current with is passed through a series of rectifier diodes and converted to direct current".

[TheBackyardDIYer]

Sounds like the same diagram Phil-l posted earlier...

http://s892.photobucket.com/user/e39...tml?sort=3&o=0

[MrCreosote]

Discovered a massive TYPO in my Title!!!! Said "Chart" instead of "Charge" so you can kiss this thread goodbye for title searches.

So I contacted the site asking then to change it and the message was refused because I was banned.

When it rains it pours.

The change needed is replace "Chart" with "Charge System SCS" like I modified my initial post #1 in this thread.

[12Ounce]

Yes, it is the same diagram. (Guess I took a nap!)
.
So I suppose my generating system is part of the "smart charge" community of generating systems. Early on, I also had a bit of trouble keeping a battery "up" ... it seemed any extra load left on, and the battery was dead in a couple of hours. I now live trouble free ... don't really know why there has been a change, perhaps I live a bit in fear and check the system often.

The alternator has been replaced a couple of times ... after battery voltage to be found low as engine idles. I use 13.75 volts as a "target" at idle. I have usually replaced alternator from AutoZone .... buying the largest "ampere rating" available, if there are choices. I keep critical eye on the battery and will replace if overnight-at-rest voltage goes below 12.3, or so. I buy batteries from Sam's club. When I take an old battery in for replacement, they usually test and find it is indeed faulty. I get about 3-4 years out of a battery.

[TheBackyardDIYer]

Creosote,
I'm sure there are enough "keywords" in this post that anyone searching will be able to find it, and if they know what they are looking for, they should still understand even with the typo.

12Ounce,
I think the SCS started in 1997 (from something I read), so yes, you are included in the fun...And you check for a low of about 12.3v? I think when I went and checked yesterday morning, pre-startup, it was around 11.5 or something...Is that an indication of a bad battery? I did get the B1318 (I think it was) code. I really don't want to dish out $150 for another battery right now...Guess I'm about to go check it again and see, then to AutoZone for a test...

Update: Just went outside and checked and my voltage is 12.1...I haven't driven the van since yesterday...time for a new battery?

[MrCreosote]

If you check your battery voltage in the morning and it is below 12v, I would guess it is NOT the battery and that you have a SCS that is not properly charging the battery.

Ironically, even if SCS does 14.7 initially, it cannot maintain this for a time sufficient to fully recharge the battery. If you run the engine "long enough" you will fail to get the 14.7 and end up with a charge voltage as low as 12.5 or even lower.

End result: battery is NEVER fully charged.

What is insidious about this is that the charge light never comes on and if you check the battery, you most like do it NOT after a long period of operation where the charge has degraded.

So a lot of people never realize the SCS is failing.

Way to go Ford.

Regarding the TYPO: I do searches like "Smart Chart" Titles only to cull out the off topic. I really need to get that title changed. WOW, I just did the typo again! Problem is I've been typing so fast for so many years that I don't type keys but words. So I succumb to WORDO's rather than TYPO's! HaHa

[TheBackyardDIYer]

Originally Posted by MrCreosote

If you check your battery voltage in the morning and it is below 12v, I would guess it is NOT the battery and that you have a SCS that is not properly charging the battery.

I guess that makes sense...I still need to get my battery tested just in case I suppose. I will try and get AutoZone to do their little analysis while the car is running...although with the SCS I don't know if they will be able to see if it is working properly anyway. Then I will take them (alternator and battery) out and get them tested individually.

Originally Posted by MrCreosote

Regarding the TYPO: I do searches like "Smart Chart" Titles only to cull out the off topic. I really need to get that title changed. WOW, I just did the typo again! Problem is I've been typing so fast for so many years that I don't type keys but words. So I succumb to WORDO's rather than TYPO's! HaHa

I suppose your right. I usually just search for a topic within all threads rather than by title as sometimes the titles aren't direct enough (which I am guilty of with my two threads...guess I need to change the titles to suit the post better).

[12Ounce]

I suppose to check battery voltage one should do two tests .... one after engine shut down, waiting a couple of hours for cool down ... and a second check many hours later, perhaps overnight ... to see how much voltage was lost in those rest hours.
.
I checked my battery before starting this morning...32F ... 12.01 volts. And at engine idle ... 14.56 volts. I think my alternator is burning the battery a bit .... I need to follow up with a thorough battery test.

[TheBackyardDIYer]

I did another test this morning because I had to drive more than four miles this time...

Before initial start-up at 56F the battery was 11.73v...after starting 14.84v. After driving for 30 minutes it was 14.77v before I turned off the engine and 12.33v after shutting off. Messed around in Home Depot a few minutes went to Walmart (about 200 yards from HD) and then drove back home 30 minutes...Checked it running again at home 13.48v running and 12.60v after shut-off.

I will check it again before I turn in for the night and then again first thing in the morning to see the difference...I need to go to AutoZone and try and find a socket so I may let them test it while I'm there...

[MrCreosote]

PIN 1: Alternator Feedback:

Square wave,
0 to -1v,
Period varies about 20% at a frequency of about 1 Hz,
Pulse Width is about 70% 0v and 30% 1v.
Pulse Width 1v duration appears fixed - the 0v duration is varying.

PIN 2: ECM request:

[EDIT:]

I barely caught this because at the sweep for the reference square wave, this burst was just a faint spike. Only when I increased the sweep and caught with trigger could I see what it was.

Intermittent 25ms burst
0 to -1.4v
Period of burst is about 6 seconds idling and with all loads on, erratic 1-3 seconds.
About 10 cycles of square wave in 25ms
Duty cycle seems even and independent of load (this is difficult to see because I don't have a storage scope.)

PIN 3: 12v Reference

No measurable difference from battery, <0.01v (limit of digital meter)
_____________________

CONCLUSION:

System is massively haywire. Bad component is not obvious.

TO DO:

Check wires to ECM.
Search internet for "dead signal smart charge" to find what other people have found.

[MrCreosote]

Who knows what happened. I pulled the connecter off the PCM (proper name, not ECM)
inspected the pins, they were greased, and put it back on.

Then I checked waveforms again and found some changes:

PIN 1: Alternator Feedback:

Square wave,
0 to -1v,
Period was now rock constant (instead of varying about 20% at a frequency of about 1 Hz,)
Pulse Width Duty Cycle was about 70% 0v and 30% 1v.
Duty Cycle now varying maybe 20% at about 2 Hz.

PIN 2: PCM request:

[EDIT:]

I barely caught this because at the sweep for the reference square wave, this burst was just a faint spike. Only when I increased the sweep and caught with trigger could I see what it was.

Intermittent 12ms burst (instead of 25ms)
0 to -1.4v
Period of burst is about 6 seconds idling and with all loads on (no more erratic)
About 5 cycles of square wave in 12ms
Duty cycle seems even and independent of load (this is difficult to see because I don't have a storage scope.)

PIN 3: 12v Reference

No measurable difference from battery, <0.01v (limit of digital meter)
_____________________

BATTERY VOLTAGE OBSERVATIONS:

Now a voltage of 14.05 to 14.2 is maintained for all loads.
When a big load is sudden, the alternator over a period of 5 seconds smoothly comes "on line."
Voltage reduction with run time problem not observed (however, on the last turn engine off then on in the hopes of demonstrating a new, lower set voltage, the voltage hesitated at 13.8 (which would have been a typical reduction after a stop/start) for 1-2 seconds and then proceeded to 14.1 volts.

CONCLUSION:

I seems to be maintaining voltage correctly. Even the 14.7 start up voltage is not present, however it is now 50 degrees out and not below freezing.

However, it does not have the wave forms that all the Smart Charge articles describe. But then, neither does it have a Silver Calcium battery which is always part of these articles.

I'm going to put the cowl back on and drive it and see if it continues to charge over 14v.

While I can't explain what happened, it may be working properly. And while frustrating, I can't complain about burning $100's fixing it.
System is massively haywire. Bad component is not obvious.

[MrCreosote]

FURTHER THOUGHTS:

REQUEST SIGNAL, pin 2:

If this is a burst every 6 seconds, it cannot be related to controlling the alternator's response to loads.

The only thing that can be updated every 6 seconds would be the Temperature Compensated Set Voltage.

This would imply that the response to loads comes from the alternator's internal electronics.

This would also imply the Pin 2 wire to the PCM is functioning properly. No wire problem could cause a 12ms burst every 6 seconds.

RETURN REFERENCE, Pin 1:

Key realization here is that given all observations, it cannot be concluded that the wire to the PCM is OK.

Wire integrity to PCM MUST BE CHECKED.

__________________________________

NEED SHOP MANUAL:

With all the discussion of Smart Chart problems, I have never come across anyone that has obtained information from the Shop Manual.

I would think that the SM has all the technical information to diagnose this system.

Does ANYONE HAVE A SM that could see what information is available?

____________________________

Just ordered a Shop Manual.

[12Ounce]

Take me a while ... I will dig it out.

[MrCreosote]

12ounce,

Oops, should have refreshed the thread to see you had one.

If yours is handy, I still wouldn't mind knowing what is in there since who knows how long it will take for them to ship mine.

BTW, I don't mind buying the manual since I got a good deal on eBay for $32 shipped.

Of course, I'm planning on selling my Windstar this Spring, so this problem is not at all welcome!

If worse comes to worse, I'll take it to the local experts (Murray Electric) with the cowl removed and let them diagnose it for $65 an hour. (Don't want to pay them $65 an hour to r&r the cowl :o)