shaystudies

Whats up my fellow Benzers!
So for the past couple months i have been getting a warning sign for Battery/alternator, i took it to the stealership and they told me everything looked fine. The alternator passed the test and battery was brand new (replaced it 4-5 months ago). As winter came along the sign started coming much more frequently probably about 2-3 times a week in the morning at a cold start this was when I used to live in San Jose where the weather wouldnt really get that cold, however i recently moved to San Francisco and as many of you must know it gets cold as SH** out here and yesterday while stuck in traffic the sign for batter/alternator came back! This never happened while i'd be driving and then the car started hesitating in traffic. It would almost feel like it was gonna turn off and i'd be stuck in downtown traffic at 6:00PM : but luckily i was able to drive back home. As soon as i got home i started searching for threads with similar problems where people said it might be the voltage regulator. I wanted to know if any of you guys have had an experience like this and if so what did you do!?

i am kind of freaking out since i have to go back to San Jose tomorrow (45 mile commute) and i dont want to be stuck on the side of the freeway.

shaystudies

bump

phister

make sure your battery is giving out constant voltage off load and under load. is the car throwing any CELs

shaystudies

No, No CEL's at all. How do i check the voltage load?

phister

you can get a voltage reader or can read it through our gauge cluster... forgot how to get to that menu.

shaystudies

I believe i read something about that, "Dyno Mode"? you put your key in position 1 and then press reset 3 times? The problem is i dont know which button is the reset button...

phister

reset is the black knob on the actual cluster on the left side that resets your odometer and lighting for the gauge cluster. just push it down.

shaystudies

Okay, and what am i looking for as in how many volts should it read?

mtrevelino

My 2006 cdi with its original battery reads 12.2 volts when I finally figure out how to get to the voltage menu. When the car is running is should be anywhere from 13.5 up to 15.2 volts. Mine is at approximately 14.5 volts when running.
Mike T.

shaystudies

Okay, sorry for the delayed response guys its finals week! So i checked the Voltage and my car reads 11.9 volts w/o any load (no start) and reads 10.9 Volts when running. any guesses what this maybe?

sammydragon3

yes u need a voltage regulator urgently...does it struggle to start?

dont go to the dealership.... find an indy or someone to change the alternator

dont spend more than 400

shaystudies

No not at all, I'm actually driving the car now. Yeah ill get the alternator changed its a Valeo. Also I called an Indy shop And he said that I can either put Bosch or Valeo that right? If so which one do you recommend? And since I'm driving the car right now should be okay right? Not going to die on me? Sorry I'm just a little bit freaked After reading the whole urgently part LOL

sammydragon3

Valeo is what mercedes put in from factory..so valeo all the way

it might die on u when driving since if the alternator stops charging the battery its gunna die...u have very low voltage when driving

shaystudies

Update** while I was driving the car threw a CEL and BAS and ABS signs came on. I just pulled over in the side and doing a stop and go every 2-3 miles. Only 30 more miles to go..

samaritrey

Valeo or Bosch some say they had issues when changing between the brands others have not had the issues. Both came as OEM in the w203's.
Good Luck and keep us updated

C230 Sport Coup

Usually it's just the brushes that go bad.
The brushes are part of an assembly that includes the
brushes and voltage regulator.
Check with Seacoupe he found an inexpensive souce for the
voltage reg module.
The module is just like 2 screws on the top of the alternator.
Costs is less than $100.

OR you can take it to an auto electrics shop and have it rebuilt.

shaystudies

Another update, so car didnt die or anything but since it started throwing ABS BAS and CEL lights I decided its better to just get it towed so I can prevent other damages. Took it to an Indy and the estimate was 500 bux including the new belt. Took pix!

shaystudies

Estimate for a new alternator**

Boom vang

Sounds like classic VR issues. 2004 C class has the crappy and defective prone Valeo alternator that had issues for 2003-2004. This French manufacturer is anything but Bosch and also the source with antifreeze in the auto transmission from their batch of defective rads (it is no wonder why I hate French cars - owned one once, and parts made in France). I changed mine ~ 1.5hrs there is a thread somewhere in the forum about tips and a DIY to do the job that I contributed to. Here is a source for the VR which is far cheaper than getting it at the dealer , it is an OEM part http://www.americanenginesco.com/ser...c-class/Detail the rest of the alternator usually stands up so unless the bearings are shot you can get away from just swapping the VR. HOWEVER expect to get an SRS error once you disconnect the battery and the alternator which will cost you about $80 to get re-programmed with a Star diagnostic

If you are going to replace the alternator, replace it with the same type that came with the car, while it does not make sense it seems that those that replaced their Valeo with a Bosch ended up with problems and vice versa as it throws errors

shaystudies

I just thought changing the whole alternator would be a better route since the car has pretty high mileage about 135k

Boom vang

that is not high mileage, if you are handy and have an hour and a half, $70 to replace the VR is certainly a lot cheaper than paying $500 for an indy to replace the alt

shaystudies

Do I need to take out the alternator to swap the VR?

C230 Sport Coup

There's some DIY's around on removing the alternator on 2004 C230.
It's different than mine on 2002. But I can tell you I can pull mine in about .5 hr.
You might need to pull it to get access.
It just depends on whether you have money to burn or not.
500 isn't a bad price from a mechanic.
But you could DIY for much less. What part of SJ are you in?
I did a lookup on EPC it shows the VR as PN A0031543406.
Thats for a bosch. They don't show anything for Valeo.
I pulled a VIN from Ebay from a 2004 C230 to get the pn.

Parts.com has it for $66 + shipping etc. 69 from getmercedesparts.com
which is a dealer in Maryland. Or you could buy a rebuilt alternator for
around 125 online. Try calling Paeco (Pacific Auto Electric) in Sunnyvale,
and see if they have any sitting on the shelf. They rebuild on the spot for about 150.

shaystudies

Thanks for all the help guys really appreciate it. C230 Sportcoup, i live off 680 and Berryessa. I was talking to my service advisor at Smythe european yesterday and asked him about the VR and they recommended me to just change the entire alternator to be on the safe side, so i guess its cool. plus its finals week, so i dont have any time nor the tools to do the repairs myself. C230Sportcoup, thanks for all the research though brother.

C230 Sport Coup

Well, just was thinking I love closeby and could help.
But if money isn't that big a deal, then go for it.