jwalton

Anyone have experience with this in the GT3 996 ? Was coming back from Hershey and the voltage guage was dropping to 10 volts. Stalled the car accidentally and the battery was dead when I attempted to restart the car. With help we pushed the car to jump start it and drove 30 miles to my home. Put in a new battery and the car seemed fine but then the alternator light came on and the voltage guage started to drop again so I parked it. Input appreciated. thanks Jon in delaware

DupaHead

Have you checked the voltage of the new battery? If it's dropping then you most likely have a bum alternator. Haven't had this experience in my GT3. Are you running any additional electronics that may be putting a strain on the electrical system? Check all ground connections as well, there is a possibility something came loose.

jwalton

Havent checked any of that yet but its a good suggestion before taking the time to remove the alternator only to find its NOT the problem. Can any testing be done on an alternator while its still in the car?
To your question about checking the battery to see if the Voltage has dropped. what i do know is the Voltage meter in the guage cluster started to read less than 12 volts after a while of running on the new battery. this indicated to me that the voltage was dropping and the alternator was not charging. No additional power equiptment is installed in the car. Bone Stock. thanks for all your input. jon

DupaHead

Check the battery voltage directly (meaning use a multimeter/voltmeter directly on the battery contacts). If the voltage is dropping and your connections (battery side, alternator side) are good, then chances are your alternator is kaput.

You should be able to check voltage output off the alternator with the car running (may need to take the airbox out). Check if it is even possible to gain access to the alternator output cable. If it is, the alternator voltage will read above 12volts..

jwalton

Awesome thanks for your suggestions. I will try those ASAP. jon

jmla

Any updates on the issue? I just experienced the same problem tonight. I recently reinstalled my battery after having it recharged.

Holger B

I'm having a similar issue. Is alternator replacement a DIY? Where's the best place to get one and how much should I expect to pay? Is it the same as the regular 996?

Thanks.

jmla

Hi Holger,

I've read that removal is pretty straight forward (if you're mechanically inclined). I believe that there is a thread on our 996 forum and also on renntech. I've been researching alternators for a couple of days now and this is what I have found:

New Bosch from Porsche (997.603.012.04) $1275
Rebuilt Bosch from Porsche (997.603.012.DX) $1115
Rebuilt Bosch from Pelican (996-603-012-2X-M14) $389
Rebuilt Aftermarket from Auto Zone $250-$300
Rebuild my Bosch unit at California Alternator & Starter $150

I've decided to have mine rebuilt locally because I'm broke. If my rebuilt unit happens to fail, then I will do the rebuilt Bosch from Pelican on the next go-around.

Good luck, let's keep this thread updated.

Jeff

Holger B

Jeff, thanks for the info. I saw your thread on the other board. I'm looking into a few options and will probably go the same route as you.

jmla

Well, I had the alternator removed today and I was surprised by two things:

1. It's a Bosch 150 Amp unit (the owner's manual states 120A)
2. It had a fixed pulley (like for a Tiptronic) and not a clutch type pulley with bearings.

I dropped it off at the electric shop to be rebuilt, I'll update once it's back in the car.

jmla

I had my rebuilt alternator reinstalled today and everything seems to be operating properly (I'll keep my fingers crossed). For reference, the part number on my unit is: 997.603.012.00 (150 Amp / fixed pulley). Tom at Lucent (310.733.7324) did the R&I and Henry/Robert at California Alternator & Starter (310.530.6410) did the rebuild. I'd also like to mention that both shops were a pleasure to deal with and offered very fair pricing.

DavidNR

Thanks for sharing jmla. My car is also out of warranty so this is good info!

Holger B

Yanked mine out today and brought it to a local shop for a rebuild. Easy DIY so far. Less than 1 hour to remove, $168 for the rebuild.

Disconnect battery & remove airbox

Holger B

Turn tensioner bolt clockwise and slip belt off alternator, then remove pulley below alternator

Holger B

Remove oil filter bracket and the 2 bolts that hold the alternator in place