Alternator gone bad??
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From: AL,IL, GA, CA
CLS, SLK, ETC
Alternator gone bad??
Few months ago, I replaced the battery because it was deeaaadd for some odd reason.. My mech and others thought the voltage regulator, alternator might went bad..... However, after installing a new battery, everything seemed OK (I checked the voltage using dyno mode). System was charging properly.. Well today, I went out for some go kart action with my bud who just purchased a Brabus CLS K8. CAr did feel a lil slow (did couple 150+mph runs on the interstate though.. It def felt slow) and on my way home, Battery / Alternator warning light came on again…
When I got home, I checked the vol again (dynometer) and it was 11.8 when the car was on...Even when I rev'd the engine, Vol stayed same. That proves that the system is not charging properly.
Is it possible that some of cable got loose on the way home? I just don't see how alternator on our car can go bad on a 05 model cars. Even my 1999 hyundai never had this issue and still rocking on stock battery at 90,000 miles.. My C55 has about 35k miles now.
Any one else had this issue and share what your local dealer did to resolve this problem.
It’s really hard and expensive to get C55 parts in Korea. So if it’s the alternator, I’m thinking about getting one from the US and ship it over here
-------------
So I was reading the owners manual and saw something interesting.. Battery / alternator warning can be triggered if "POLY-V-Belt" is damaged...
I really doubt that is the case for me though..
When I got home, I checked the vol again (dynometer) and it was 11.8 when the car was on...Even when I rev'd the engine, Vol stayed same. That proves that the system is not charging properly.
Is it possible that some of cable got loose on the way home? I just don't see how alternator on our car can go bad on a 05 model cars. Even my 1999 hyundai never had this issue and still rocking on stock battery at 90,000 miles.. My C55 has about 35k miles now.
Any one else had this issue and share what your local dealer did to resolve this problem.
It’s really hard and expensive to get C55 parts in Korea. So if it’s the alternator, I’m thinking about getting one from the US and ship it over here
-------------
So I was reading the owners manual and saw something interesting.. Battery / alternator warning can be triggered if "POLY-V-Belt" is damaged...
I really doubt that is the case for me though..
Last edited by Quicktwinturbo; Nov 2, 2008 at 05:07 AM.
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Joined: Jul 2007
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From: East Bay, Bay Area
2002 C32, 2012 S550
Mine went out about 6 months after I had battery problems due to my seat module draining my battery all the time.
My mechanic said my alternator was probably working overtime for a long while while I was having problems and made it prematurely fail.
Could be different for you, but just sharing my experience.
My mechanic said my alternator was probably working overtime for a long while while I was having problems and made it prematurely fail.
Could be different for you, but just sharing my experience.
Thread Starter
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From: AL,IL, GA, CA
CLS, SLK, ETC
Actually, my mech once mentioned about the vol regulator... But once I got the new battery, everything seemed fine
.. I hope its the reg.. Cuz I heard new alternator for our car is very pricy.. 
Gramma B,
Thank you for your comments.. I'll check that as well
Junior Member
Joined: Jul 2007
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From: tokyo
c55
i'm not sure what the problem was but i just had an electrical problem in my c55 fixed under warranty. the battery died and when we tried to jump start it, wouldn't jump start at all so ended up towing it to the dealer. not sure if this is related to your problem or not but for what its worth...
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
Can't a
shop test the alternator under load and tell you if the stator or diode is functioning or the VR is good or bad?Any good auto electric shop should have the meter.
If not a bosch rebuilt with warranty for the C55 is only $250 have it boxed up and posted over.
Inspect the belt,don't jump it via the battery,don't jump it via the underhood post with the key in the ignition.
If not a bosch rebuilt with warranty for the C55 is only $250 have it boxed up and posted over.
Inspect the belt,don't jump it via the battery,don't jump it via the underhood post with the key in the ignition.
Thread Starter
MBWorld Fanatic!
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From: AL,IL, GA, CA
CLS, SLK, ETC
Thank you all for your comments.. I did take to to my mech today and problem was solved by replacing old Voltage reg with a new one. Quick $250 fix.... ......
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From: Brooklyn
2009 Mini Cooper Clubman S
The same warning lamp just turned on for me today, what is the test that they did to determine whether it was the alternator or voltage regulator? Is there something I should be looking for in Dyno mode to clue me in?
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Thread Starter
MBWorld Fanatic!
Joined: Jun 2006
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From: AL,IL, GA, CA
CLS, SLK, ETC
Just take it to the dealership.. It's hard to tell.. More than likely, it's the regulator.. Alternator won't go bad so quick on 05-06 cars... If you are out of warranty, change the regulator first since it doesn't cost alot... Good luck!
Senior Member
Joined: Oct 2008
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From: Brooklyn
2009 Mini Cooper Clubman S
Yeah, out of warranty, so I will definitely instruct the shop to try the regulator first. I'm really hoping its not the alternator, after buying all those christmas gifts and flying back and forth to chicago, my repair the C55 fund is running dangerously low.
Super Member
Joined: Sep 2007
Posts: 784
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From: Miami
Bicycle
Like quick said it's hard for a alternator to go out so soon. Believe me when it happen to me I was scared after see the price of the alternator. Put a screw driver behind alternator to see if it's magnatizing.
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From: Tampa, Florida
2005 c55amg, 2000 clk430, 2002 clk55amg, 2008 clk63amg black series
I had the same problem a few months ago...i had it towed to the shop...and they did some tests...it turned out to be the sams? we have 2? one under the hood, and one in the trunk? aparently they got wet, but since i was under warrenty they replaced them.
