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petes

Is this a dead alternator?

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Hi All

I was driving home tonight in my '02 996 C4S and all of a sudden the battery/generator light popped on, and I noticed the charge had dropped from its normal 14v to an unhealthy 10v or 11v. About 5 miles later, as the charge dropped off, various things shut down - PSM, ABS airbags etc.. I got home OK, turned it off and tried it again, and got the ominious click. I've charged the battery for a few hours - enough to start the car, but the battery/generator light was still on and the charge voltage was about 11v.

Is this a dying alternator or might it be a dying battery? Although I've read here strange things with batteries, it seems strange that a) it started whilst I was happily hacking down a highway and B) that even after a charge, the charge voltage is low. However, I guess it could be that the battery's gone high resistance for some reason. I'll see about getting the battery tested tomorrow but just wondered if anyone had any comments.

Thanks

pete S

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Hi All

I was driving home tonight in my '02 996 C4S and all of a sudden the battery/generator light popped on, and I noticed the charge had dropped from its normal 14v to an unhealthy 10v or 11v. About 5 miles later, as the charge dropped off, various things shut down - PSM, ABS airbags etc.. I got home OK, turned it off and tried it again, and got the ominious click. I've charged the battery for a few hours - enough to start the car, but the battery/generator light was still on and the charge voltage was about 11v.

Is this a dying alternator or might it be a dying battery? Although I've read here strange things with batteries, it seems strange that a) it started whilst I was happily hacking down a highway and B) that even after a charge, the charge voltage is low. However, I guess it could be that the battery's gone high resistance for some reason. I'll see about getting the battery tested tomorrow but just wondered if anyone had any comments.

Thanks

pete S

Pete,

Is this your original battery?? If it is, then I would bet it is the battery going bad with a shorted cell. Even if it is a replacement, I would guess a cell has gone bad. Easy way t odiagnose is to jump the battery in the car and see if it starts and voltage gauge is back to normal.

Good Luck!! demosan :cheers:

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Easy enough to have the battery tested at your local auto parts store. I have seen batteries less than 1 year old go bad.

Oh man, this is almost exactly what happened to me. On Sunday the car was great on a long drive, on Monday the exact problem happened, low voltmeter, etc, and all the electronics went to hell. had to replace the alternator and battery. good luck with this, please advise what you find out....

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Just realized there are two current threads running re battery/alternator issues. could this be an epidemic?

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Just realized there are two current threads running re battery/alternator issues. could this be an epidemic?

Well, in my case, it's not a dead battery - all's pointing to the alternator. Dropped it into my local indi this morning - they told me that they've had quite a few '01 and '02 facelift 996's in recently for new alternators, so it may be just things of a certain age starting to pack up :(

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Just realized there are two current threads running re battery/alternator issues. could this be an epidemic?

Well, in my case, it's not a dead battery - all's pointing to the alternator. Dropped it into my local indi this morning - they told me that they've had quite a few '01 and '02 facelift 996's in recently for new alternators, so it may be just things of a certain age starting to pack up :(

In my case, the Battery/Gen light didn't come on; but other warnings like PSM/ ABS came on for about a second and went away. I replaced the OEM battery... hopefully that's it.

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My turn tonight...

My 99 C2 seemed slow to turn over after a short trip to the shops, but she did actually start. Then on the 4 mile ride home, I noticed a brief display of one of the lights on the dash, couldn't tell which one it was too brief. A mile later, I saw the ABS light come on, along with the battery light. Ut oh. Look over at the volt meter, and it was way down. 10V, whereas it's usually about 13.5V. Arggh. Turned off fans, lights, etc, limped home (with the dash warning lights sometimes on, sometimes off), parked, and got the clicking when trying to start again.

We had just done a 200 mile trip last weekend, glad it didn't happen far from home.

I did replace the battery about 6 months ago, and had no problems in the mean time.

I'm guessing alternator, but maybe I'll take the battery in to be checked - it's under warranty anyway.

If the battery is OK, I'll try the DIY alternator replacement. Wish me luck!

-James.

Edited by jamesgood72

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Quick question - If I get a replacement alternator without they pulley, is that difficult to remove from my old core, and put onto the new unit?

ALso - I think this is the unit I need. Correct? 12093 also appears to be the part number on Autozone as well.

http://www.napaonline.com/MasterPages/NOLM...ernator+-+Remfd

Thanks,

-James.

Edited by jamesgood72

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Quick question - If I get a replacement alternator without they pulley, is that difficult to remove from my old core, and put onto the new unit?

ALso - I think this is the unit I need. Correct? 12093 also appears to be the part number on Autozone as well.

http://www.napaonline.com/MasterPages/NOLM...ernator+-+Remfd

Thanks,

-James.

When you change the alternator consider also putting in a new battery. I've had good luck with Interstate over the years....

Edited by judgejon

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I got a new battery a few months ago. I'm guessing that the failure of that battery caused these problems with my alternator. I've since had the battery checked, and it appears to check out good.

Anyone know how difficult it is to change the pulley? I suppose it would be OK to swap the pulley from my old alternator to the new one, if it doesn't come with one?

Pelican Parts has a different part listed for tiptronic and manual cars (mine is manual) - and the manual version is $75 more. What would the reason for that be? Autozone seem to supply without the pulley. Is the free-wheeling pulley $75?! Sorry for all the questions...

http://www.pelicanparts.com/catalog/shopca..._ELchrg_pg1.htm

-James.

Edited by jamesgood72

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James, sent you a pm with the info. Don't forget to board up the windows! My parents are in Kendall and getting ready for Fay.

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Fix pulley is for Tiptronic ( never in combination with plastic rollers ), free wheeling pulley for manual transmissions. All the alternators comes inclusive pulley over here, can't tell you more.

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Thanks everyone.

Anyone in the US ordered an alternator recently? I'm unsure of which part to order from the big local parts places, they don't seem to specify which alternator is for which transmission type car. And of course, the local sales people can't help. Anyone got a part number for the alternator for a '99 manual tranmission C2?

Cheers

-James.

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I only see one genarator in the PET for 1999, part number 996 603 012 01. This is in page 508 of:

https://techinfo.porsche.com/techinfo/pdf/e...996_KATALOG.pdf.

Would vertexauto.com have it? I think they are out by the airport in Miami. I just checked, they do for $275

http://www.vertexauto.com/ListItems.aspx?R...rical&&

Edited by Izzy

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I called vertex, they have one in stock. Thanks for that tip. I think I will get mine out, and take it down there, after this storm passes. Thank you!

-James.

I only see one genarator in the PET for 1999, part number 996 603 012 01. This is in page 508 of:

https://techinfo.porsche.com/techinfo/pdf/e...996_KATALOG.pdf.

Would vertexauto.com have it? I think they are out by the airport in Miami

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OK, I'm back. Sorry. :)

I've got everything disconnected, and all the bolts out of the mounting points, but it's still stuck in the car. The front right mount is now loose, as is the left mount, but I'm having a devil of a time man-handling the thing out. It appears that I can't move it high enough to move it over the mounting points. The intake manifold (at point X on the picture below) stops it from going any higher. Any ideas?

Thanks,

-James.

post-20264-1219194489_thumb.jpg

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James, did you do the clockwise rotation and pulled out slowly? There should be a connection in the back you got to disconnect

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Well, I got it out. Definitely had a bit of a fight with it though, and unfortunately I broke the coolant connector that runs to the right of it. Still, it's out and the coolant fix should be easy, I hope. Now I have the fun of getting the new one in! THanks for your help.

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New alternator is now installed. I got it from vertexauto, Izzy, they were great.

I just have to fix the coolant hose. I have a connector to join the two pieces, but I can't get the old connector on the bottom piece of hose off. I've included a picture of it. WHat's the trick to removing that fastener?

Really appreciate any help - I'm getting there with renntech.org's help!

-James.

post-20264-1219366440_thumb.jpg

Edited by jamesgood72

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It looks like it is factory crimpt, perhaps you would have to cut it and ause one of those fasteners with a screw.

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Thanks hi8ha. That's what I was thinking, there doesn't seem anyway to remove it without a sawing it apart. I was surprised it wasn't a reusable clamp.

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OK, everything is back in and everything seems to be working - we have charging happening, and the other accessories seem to work. However - the car will not idle. This was not a problem before. If I hold the throttle at 1000 rpm all seems good. But it will not idle there by itself. Could I have changed the throttle cable adjustment inadvertently? I'll search around for this problem, but if anyone has any input, I'd appreciate it...

I've included a picture below of the new alternator in place, and the fix on that coolant pipe that I had to do.

BTW - here is a list of threads that I've found useful for anyone else that attempts this job :

http://p-car.com/996/diy/sai/mainpage.html

http://www.renntech.org/forums/index.php?s...&hl=brittle

http://www.renntech.org/forums/index.php?s...&hl=brittle

http://www.6speedonline.com/forums/996turb...ve-replace.html

http://www.renntech.org/forums/index.php?s...amp;hl=recharge

http://www.renntech.org/forums/index.php?s...c=9299&st=0

THanks,

-James.

post-20264-1219515565_thumb.jpg

post-20264-1219515585_thumb.jpg

post-20264-1219515609_thumb.jpg

Edited by jamesgood72

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I put a code reader on it, and got a P0102 - maf or vaf circuit low input. I believe that's the MAF just above the alternator, right?

Anyway, I drove the car around the block, it drives fine, and appears to be charging. It's just that it won't idle. Gah.

When I tried to remove the more accessable line from the MAF, the line snapped, it was extremely brittle and a little force to try and remove it from the rubber connector snapped it. I used a piece of flexible hose that the Porsche parts place gave me to reconnect it, and thought all would be OK. You think that could be causing this bad reading?

-James.

Edited by jamesgood72

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