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YOUR RESEARCHABS and Battery Light, 16 volts?!
Leading reported evidence
Replace 996 alternator
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I have read that some have replaced the 996 alternator with a 997 one specifically an al0815n from bosch.
Leading evidence: 'Replace 996 alternator' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'soapy water in engine compartment around the alternator' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check any battery drainage' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
Yes, about a year ago I replaced the 996 alternator (Bosch AL0812N) on my 2004 C4S, with the 997 alternator (AL0815N).
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It went perfect today car ran like nothing was worng with it.
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soapy water in engine compartment around the alternator
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Suspected cause
I would suspect soapy water in engine compartment around the alternator.
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Suggestion
Battery cannot get that high itself - and if you are getting 16V charge - means the alternator is working - but regulator is bad (i'm not sure on my 996 if the regulator can be replaced separately from the alt.
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Suggestion
Or maybe the drains on the sides of the water shield under the engine grill are clogged letting water collect and run into the engine bay onto the alternator?
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42 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
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Outcome without a verified action link
Went around the block back home, turn the car off waited few sec and started again, all was back to normal, get going down the raod, and again both lights and 16 volts.
Hello Guys
Need some help
Today I washed the car, took the hard top off, raised the soft top, then family jumped to go for our first every ride with the top down. I started the car put the top down and started to drive away, and the ABS and Battery light came on and the volt gauge was at 16 volts.
Went around the block back home, turn the car off waited few sec and started again, all was back to normal, get going down the raod, and again both lights and 16 volts. Go Back home turn it off wait then back on and lights flicker on and off then stay on and volts back up to 16.
Any ideas? My guess would be the Alternator, but why the ABS light?
99 996 C2 24,000 miles
So I go back out and start it again and all is fine, then I give it some gas and the lights come on volt meter acts normal, I turn the air cond and fans on the lights go out, I give it some gas and the light come back on the let off the gas and the light go off, volt meter seems to be working as it should goes up a little with higher rpm's then come back down.
?????
Ok, I waited a couple of hours and started the car and everything was back to normal, no lights volt gauge right at 14 volts, took it out for an hour or so drive and all is well.
So now I'm thinking it had to be water from the car wash (hand wash in driveway) that was shorting something?
Any ideas where or how I start looking for what the cause was, anyone had something like this happen to their car? I really don't want to get stuck somewhere the next time it rains. Never had an issue with washing or driving in the rain before.
Battery compartment is not sealed. Only the carpeted part is sealed.
There are four drains in there, battery box, to let the water through to the ground. Always good idea to check them to be sure not clogged?
I would suspect soapy water in engine compartment around the alternator. Probably never get it to happen again.
I cleaned out the front drain plug around the battery earlier this spring (they were not draining), I did look after bringing it back home on the first run and nothing look really wet, some drops of water here and there but no real soaking.
I'II keep my finger crossed on the "Probably never happen again"
Was very disapointing 1st top down ride for the kids told them we were going for ice cream! LOL got two driveways away and turned around! LOL I ended up taking them in the Dodge made them happy, but I was still pouting!
Your (USELESS!!) volt meter either reads the average voltage or the peak voltage.
What you really need to know, see, is the voltage ripple that results from the regulator/Alternator/Battery voltage regulating PWM dutycycle. Put a few extra milliohms of resistance in the circuit, positive or negative (chassis ground), and the ripple content can get extreme. 16 volts on the "ripple"/waveform high side but 11 volts on the low side (+/- 2.5 volts from the 13.5 nominal) on the low side. Measured at the alternator, NOT the voltage "sink", battery.
The ABS, etc, ECUs "see" that low of 11 volts and "I'm otta here."
Clean and burnish the battery connections and posts and don't forget that chassis ground lug on the negative side. The front to rear electrical connections at the starter solenoid should be checked as should both ends of the engine to chassis ground strap.
Replacing with a new battery often does the trick due to removing and retightening the posts, not the new battery itself.
do you have issues with taking the key out or have to play around with the ignition?.... if so, might need a new switch.... Im thinking, its prob the car wash. Its good to start the car for a bit after a wash and dry.
Zookie, I have not had it happen again, let me know how you make out and if everything goes back to normal after the water dries up.
I have done some reading here and looks like you can get a rebuilt alternator for a lot less,,,, if that's what you end up needing.
I just had to replace the regulator on my Mercedes ML350 -120A Bosch alternator. I was surprised to see it would directly replace the one in my 2003 996 - different P part number same part. There is a DIY on one of the forums that shows three different part numbers that are the same regulator One for Mercedes, one for generic Bosch part number and one Porsche. Regulator replacement DIY for Boxster
http://sites.google.com/site/mikefoc...youralternator
Also Bosch # F 00M 145 225
well i had to boost my car this AM. Still getting the Battery Light but no PSM/ABS/BRAKE Light this time. I am geting a Whining noise from the back. Called my shop they said to bring it in to Diagnose. Most likly need a new Alternator...
What a bummer, just did a 1,200 km round trip to Montreal for F1 Weekend and eveything was 100%. Untill i washed my car to get the bugs off... Atleast thank god it happend in my Parking Garage and not out on the Road or middle of nowhere...
well after a full day of sitting in my Garage, my car is fine... very Wierd... What does this mean? is my Alternator is on its way out? Bad Battery? I dint touch anything except Boost my car twice today AM & PM...
Zookie, How did it go today, any issues?
Keep me posted, I have noticed that my volt gauge is up at 14 or just a hair above, it use to be just a little below, did you notice any change?
Do you drive yours in the rain, (I generally do not), ever had any issue's?
It went perfect today car ran like nothing was worng with it.
my Volt meter reads normal just around 13v
I drive my car eveyday regardless of weather in Sun, Rain or Snow never had this kinda of issue, only this time after i washed it, maybe i got Water on the Volt Regulator on the Alternator...
If you were getting 16V adn the guage is good (should measure it at the battery with multimeter) at that point to make sure - most likely is voltage regulator.
Battery cannot get that high itself - and if you are getting 16V charge - means the alternator is working - but regulator is bad (i'm not sure on my 996 if the regulator can be replaced separately from the alt. ?) If you were lucky, maybe something just got wet around that area and caused the regulator to malfunction - once dry it could go back to normal - but you don't want to run at overvoltage for too long - else you could damage some more expensive parts ....
Battery should be between 11.8V and 12.4v or so with ingition on, but engine off - low voltage at this point would indicate bad battery or poor ground somewhere.
WIth engine running at idle (no lights on or AC) you should be around 13.8V if regulator is working - again this might vary a little - I wouldn't worry about slightly over 14, but 15-16 is way too high (again unless it is bad guage)
Well it happend again today, washed my car, then started it and boom "Battery/Genarator Fail" no ABS, PMS light this time just the Battery Light and Whine from the back (which was there last time)... Car ran perfect since Thursaday untill this afternoon i washed it carefully not to get the back too wet with water, when i was drying it i opened the Trunk and saw not a Drop of water on the Alternator... Its really wierd... I did notice some Water in my Battery Tray and most on the stuff in and around there is Wet but not Soaked... Im really confused... Volt Read 16v while driving and just under 14v at Idle...
If you need to boost your car, either your battery is not holding charge or it's not being charged. Have you get your battery checked? If it's good, have you checked any battery drainage when car is OFF? It none of the above, most likely your alternator/regulator is failing or there's connection problem in the charging circuit.
Sounds like you are getting water on the alternator/regulator (regulator lives on the back of the alternator faces the front of the car) Is your rear sunroof drain misaligned somehow allowing/channeling water intot he engine bay? Or maybe the drains on the sides of the water shield under the engine grill are clogged letting water collect and run into the engine bay onto the alternator?
To answer another Q on this thread the regulator can be changed.
Finding a voltage regulator
Through various sources I found and confirmed that the Bosch number for the regulator in the Porsche alternator is F-00M-145-225. It would appear that this part isn’t actually listed anywhere as a separate item, although I did manage to track one down on e-bay. All is not lost though, as the same part is available under different part numbers. Various websites cross reference the above part number with the regulator for various Volkswagens from the similar years as well as Audi’s and Mercedes. For reference a commonly available part seems to be the F-00M-145-350 or F-00M-145-341 for VW, Audi, and Mercedes which fit perfectly.
These sites reference the different part numbers and various companies offer a replacement part for the Bosch part. These companies usually only have one part number and list ALL the Bosch numbers as equivalents. Here are a few of several possible sources of information. I would like to suggest that you google the part numbers yourself to double check. I have satisfied myself but I cannot guarantee 100%. I can tell you that my car is behaving perfectly with the F 00M 145 350 part.
(Ref;
http://www.woodauto.com/Component.aspx?Ref=VRG46473
OR
http://www.mercedesshop.com/shopforu.../t-187174.html
OR
http://www.jnelectric.com/bombridge....umber=F00M1453
50&manufacturer=Bosch&description=Regulator%2C+Ele ctronic )
I suspect that the different vehicle manufacturers insist that Bosch supply parts with a unique part number or that Bosch manufacture identical parts in different locations and assign part numbers to each. If anyone can give me an informed answer to this or if they can tell me if there really is any difference between them I would LOVE to know!
well teh shop tested the "Wash" and all was fine. I plan on washing on Wednesday after the Rain on Tuesday
Will let you guys know then...
Hope so too. The New Bosch Alternator looks like and shiney
Bosch Re-Built Unit was $550 plus $300 Install... You can get the same Bosch Unit online for $405 + $160 Core which will be refunded upon return... But i figured id rather give that $150 to my Faithfull Indy/Shop to which i have been a Customer for 5+ years
and they do a lot of free stuff for me
Factory unit is like $1500ish
I've been having the same issues as mjh1 and have decided to replace alternator myself. I have read that some have replaced the 996 alternator with a 997 one specifically an al0815n from bosch. Has anyone replaced their 996 (mine is a 2000 manual transmission coupe) alternator with this replacement
Thanks
Joe C.
Yes, about a year ago I replaced the 996 alternator (Bosch AL0812N) on my 2004 C4S, with the 997 alternator (AL0815N). It is a direct fit replacement. The 997 is a 150Amp vs 120Amp for the 996, otherwise the are the same size and same weight.
