I just got a new alternator and battery put in and on my way home I got the 'Charge System Fault' message 3 times (about 15 minutes).
Do you think they installed the new alternator improperly and perhaps something is loose? Is this normal immediately after a new alternator and battery are installed? or should I be taking it back for them to check?

 

You should be taking it back... you should not have a charging system fault. They may have installed the wrong alternator.. or not checked the ground, or the starter. In any event.. take it back and make them fix it.. here is some information for them

The L-terminal circuit from the generator is a discrete circuit (a discrete circuit has no splices and only one source and destination) into the PCM. The PCM applies ignition voltage to the generator L-terminal circuit. A small amount of current flows from this circuit through the generator windings to ground to create a magnetic field which starts the generator process. When the generator is at operating speed and producing voltage, a solid state switch for the L-terminal circuit in the generator opens and the PCM detects that the initial startup current flow has stopped.

The PCM expects to detect low voltage on the L-terminal circuit prior to the generator rotating at operating speed and conversely expects the circuit to be at ignition voltage potential when the generator is operational. When the PCM detects a fault (circuit shorted to ground, or circuit shorted to voltage), the Driver Information Center will display Charging System Fault.

The generator has an input to the PCM called the F Terminal to indicate the percentage of total capacity that the generator is producing. This signal is detected by the PCM as a duty cycle from the generator and displayed on the scan tool as a percentage. The PCM can monitor the generators output under all conditions to determine if it is functioning normally.

When there is low demand from the electrical system on the generator, a low duty cycle percentage will be displayed. As more accessory load is placed on the generator, the duty cycle output detected by the PCM will approach 100 percent. A normally functioning generating system will never reach 100 percent as indicated on the scan tool.

The L and F terminals are the red and grey

 

Wow you are just the guy I need to talk to. The connector from the wiring harness is labeled SFL (Sense, Field, Lamp). So when using an aftermarket alternator..such as a denso alternator. The wiring harness indicates S FR L IG. Can I hook up the S-S, R-FR, and L-IG (thus leaving the Delphi L out of the picture). I suggest this only because of what you described above...being that the Delphi L is used to ignite the ignition. I figure that it should go from Delphi L-IG and not L-L. Otherwise I would have to find a switched 12vdc straight to the IG.
Thanks

 

I just hope I really did need a new alternator.
The readings from it showed like 92 (voltage?), it is supposed to be 110.
The reason I took it in was its been over 3 yrs since last battery and the car was starting to get a little sluggish starting. i.e. sometimes it took two turns of the key to get going. So its either the battery, alternator or starter right? Only one showing below par performance was the alternator. So there goes $400.

 

The alternator (generator) does not start the car.. the battery starts the car. then sends voltage to the alternator to start the generator pprocess..
the 92 is the amps not volts of the 110 amp alternator/gen.
why is it 400 dollars out.. these alternators are guaranteed . Take it back to where you had it installed. Have them fix your charging system..IM getting mixed feelings about your post.. did you actually take it to a repair shop?? or are you just replacing things... If I read between the lines.. no one knows what they are doing with your charging sytem problems.. you may simply have a ground problem..
or a faulted battery..
If you took it to the dealer, or a reputable shop, they would not have just put in an alternator.. these alternators are almost bullet proof, the failure rate is very low...you mention of 400 dollars lost leads me to believe there is no guarantee on the repair work..???? who takes their car to a shop with no guarantee of correction.?

 

You misunderstood, I say I am out $400 because if I didn't really need an alternator then I wasted the money. I really have no clue how long these things should last. The car is a '99 with 85k miles on it. If the battery was fine, the alternator was ok and supposedly the starter was fine then I wonder what could be the issue? If I can get the charge system fault fixed then I'll see how everything else goes. If the car still starts sluggishly then I guess I'll be hitting the dealer. The alternator was put in at PepBoys only because they checked the battery for me and thats where I've gotten my batteries for the car. The dealer doesn't do batteries.

 

I get this message often. Even after a new battery & 2 new alternators. Good Luck.

 

Actually the battery supplies voltage to the starter which cranks the engine over, if your saying your engine is sluggish and sometime stake 2 revolutions before it starts then that has little or nothing to do with the battery, it sounds like someone is blowing smoke up your ...well you know

 

If you took it to Pepboys and had a charging system diagnosis. 19.95
starter, battery and alternator alternator, and they told you you needed an alternator.Any you getting a systemfault , then they dont know what they are doing... You go there to have the sytem diagnosed.
So they can put the right part in.. you pay the money so you nor just replacing items.. Did they dop a load test on the battery Did they check the amp draw on the started??
if the6y did all this and yout still having problems. then Pep boys dont knopw anything about a charging system..
if they said you need a new alternator and you still having problems take it back and tell them to fix it.. There are three or four alternators designed for C5, 2 for Automatic cars and two for MN6 cars...Pre 2000 cars takea different alternator from later models and they are transmission specific..

 

I just installed a 10353440 145 amp alternator and am also getting a "Charge System Fault" indication when I hit the higher rpm's. Normal driving (lower rpm's) it's OK. Battery is an Optima red top about 1 year old.
I noticed that the pulley hub on the new alternator has an "extension" sticking out from the hub and has a black plastic plug covering the pulley mounting bolt. Is this a decoupler of some sort or maybe a vibration dampener? I think this is the later model alternator and I have a '99. I installed this particular one since Fichtner's was out of stock on the one listed for mine.

 

You have the wrong alternator in your car lonestar, the black boss you see on the front is a clutch pulley used only for automatic cars, designed for when you go from park to drive..
The PCM reads different codes between the two alternators.. your pmc is designed specifically for either automatic or stick.. when you get an alternator they are suppose to ask if you have an A4 or an MN6 for just this reason..the pre 2000 alternators for an MN6 or A4 are 100 dollars less than for a Post 2000 alternator.. the alternator for your car a 99 MN6 is Part Number#10246623 it's a 110 amp made in France by Valeo.
and Yes they are available.. they put the wrong alternator on your car.. No pulley clutches for MN6's

 

That's kinda what I was thinking. The part about the pcm I mean. From what I can tell, Valeo was the designer and provided the OEM units and your right, the label shows "Made in France". SPO however, apparently is having the manufacturing done in Mexico as indicated by the label on this new unit.
Oh well, I was kinda looking forward to having the 145 amp unit as opposed to the 110, although I was not having any charging issues as such.
Thanks

 

I've had that 'Charge Fault Error' message for years. The last 2 or 3 I think. I've been ignoring it... it goes a way and may not appear for a month.

I'm not sure why I get it, but I don't think there is really any thing wrong... just some sort of out of range reading. If you see the message, don't get paniced over it, unless it stays on or you see your gauge for volts falling (the battery is not getting recharged).

BTW... I drive about 10,000 miles per year. So that message first showed up about 20,000 miles ago.

 

I guess Evil Twin couldn't answer my question

The alternator I believe should be an AD 244. Yes there are two types of Alternators one for Autos and one for Manuals.

I see the need for a hi ouput Alternator. I know somebody who can fit the regulator that is similar to the AC Delco/Delphi alternators to a Denso alternator. They even have one that is 150 amps. Great for us guys running Racetronix FP, KB BAPs, 1500w Amplifiers, and want to use our headlights at night.

I just need to finish working out the details for pin L and how to transfer that over to L an IG on the Denso. The 105 alternators we have on our cars should be bigger. I even was looking at the Escalade Alternator as it requires the F to the computer for the message center too. As long as the (F PIN) Field (Grey wire to Computer) is within 440 cycles per second it will not register a code on the PCM. I will know in the next week what suitable alternative will work. I was hoping Evil Twin had a little more insight on the actual signals involved with the GM Alternators and references.


In the mean time go get an alternator that is for a manual and you will be fine. I can't believe they didn't catch that...who the hell is working on your car...trained ASE...yeah right.

 

Guys,

I just swapped my alternator to a (??) 220 amp alternator. It's a custom job from http://www.canammotors.com (much thanks to forum member EatRice who turned me on to them). Art, the owner (or at least the dude who answers the phone all the time) is a real class act. He's been great to work with and answered all my questions, politely and professionally.

Here are some pictures (disregard my messy engine bay):






The piece is just beautiful. It's a direct fit for our car. They do their own machining, and get this -- most orders they receive in the morning are machined and shipped the very same day.

Note the giant chassis ground. You will need to run 1/0 gauge wire back to the battery. This is easy and can be done in less than 30 minutes, as long as you have the cable, terminals, and a 15mm socket Also, you might notice there are two alternator harnesses, one of them with a dongle on the end of it. Can Am Motors also makes this PCM bypass kit which allows the alternator to stop taking commands from the PCM and work happily on its own. Before the PCM bypass I was getting real funky voltage fluctuations. Now I basically never get below 13.5 volts, with ALL accessories running (including my 2 super sized aftermarket radiator fans which draw LOTS of power.. enough to drop my stock alternator down to 11 volts).

You can get these alternators powder coated in other colors besides red too.

PM me if any of you would like more info/pics. And if you end up calling/emailing Can Am Motors, tell 'em Tony Garcia sent you

 

Ummm...nope to the ASE certified tech, since I'm the one who installed it. The reason for the 10353440 alternator was that's what Fichtner said now supercedes the previous two part numbers. I have since returned it and re-installed my original. No "Charge System Fault" indications with the stocker, which by the way, is a 110 amp not 105.
The reason I changed in the first place was because I can just hear what sounds like a little front bearing noise, and I like to practice preventative maintenance instead of corrective maintenance, if possible.
Fichtner is going to get with GM Tech Assistance to find out what the story is on the spurious messages popping up. I hope that maybe it was just a defective unit, because I liked having the higher current capability if needed.
Robert

 

Can we buy a rebuild kit for the french alternator. with bearings brushes ect???

 

I advise every who is getting a replacement alternator: DO NOT LET THEM HAVE THE OLD ALTERNATOR UNTIL YOU KNOW THE REPLACEMENT WORKS.

Many people ended up having their original one rebuilt to finally have a correct charging system again.

 

I must have over 100 post on this topic over my 13+ years here... Many people don't listen, everyone seems to be an expert, manufacturers co0mne here offering their alternator and the design is relatively simple, if you look at the schematic yet no one can seem to get it right. I've said 100 times do Not give up your old alternator. Get it rebuilt, the discrete circuit in this alternator communicated directly with the PCM. After 13 + years, you would think that people would get it. You just cant put any GM alternator on this car just because it fits the mounting bracket, unfortunately most parts houses and auto supply stores are clueless here, they use a cross reference for mounting and not for function..
Early model C5's use this alternator, used in both A4 and MN6 models ( No Clutch pulley for A4 models ) as found in later models.

 

Yes, you can buy bearings and the regulator/brush assembly.

http://aspwholesale.com/index.php

Use the red "Click Here" on the left to search by vehicle.