hola,

been searching around a bit, and asking questions in other threads but after not finding my answer I thought it best to start a dedicated thread.

the other day after several weeks of trouble free driving my battery stopped charging. I figured it was likely the voltage regulator - so I got a new one aong with a new ground wire for the batt as the old one was trashed. when I pulled the voltage regulator on the car I noticed it was in really good shape - long brushes and pretty clean.

while I was under it I noticed what is pictured below. take note of the black plastic "box" attached to the back of the alt. and the crack....

two questions -

a) could this be the cause of my no charging blues?
b) and more importantly what the heck is it called?

I am hoping this is it. the battery looks new (only had the car a month) as does the alt.

appreciate the help!

Scott

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1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
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Lofat Productions
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well, upon closer inspection I think that the voltage regulator may be the culprit

I don't know for sure because that braided wire is bare, so I imagine that even if not connected to the solder point that if it was hitting the spring it would still send a signal... or not..

all the same - I would still like to replace that cracked piece above.

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1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
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Black box is most likely an electrical noise suppressor device. Usually a condensor.Not positive though.

Do you have a multimeter? It is pretty hard to tell sometimes without a few readings of voltage at start, idle and rev.

What are your symptoms that made you decide the battery just wasn't charging?

The cracked "object" on the back of your alternator is a condensor for noise suppression. I doubt it would cause the failure unless it shorted out, noisy radio maybe, especially AM.

I had to change alternators twice the last time mine failed. Sad fact is that rebuilts sometimes can be marginal. If your battery is severely discharged, it would be a good idea to charge it for several hours before starting it and charging solely off the alternator. It puts a lot of stress on the diodes which may be marginal on a rebuilt unit.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Where did you order your voltage regulator from?
Will

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84 300TD 4 speed, green

I'll third that, it's the condensor for AM noise in your radio.

On the subject of rebuilds, my 240D ate 2 "proline" pep boys reman alternators, one after a month, one after a week, before it got a reman bosch, the bosch is still on it to this day. If I had known about the voltage regulators back then, I bet that would have fixed the problem on my original alt.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Measure how much volatge is the alternator pulling
I had a similar problem this winter I did a couple of searches and most of the time after 2 regulator replacements the alternator is dead
I did replace my voltage regulator and it didn't fixed my problems. Now i have a new alternator

If i remember right when the engine is reving the amp should read between 12 and 15 and should be able to hold something higher then 13.
To be sure of the measuremnts do the test on a working car/alternator..

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2001 Jetta TDI .205 injectors + Upsolute "Fast car"
1983 MB 300 SD "Ze Panzer" SOLD
1997 MB 230 C

Thanks for all the replies.

I do not currently have a multimeter. I was looking at them in the shop yesterday and I figured it made little sense at that point to buy something that I didn't know how to use (surprising amount of control for me as I love gadgets)

Well, I started off with a working battery and ended with a dead one. It started fine one morning (and for the three weeks prior) and when I stopped off for fuel I pulled up to an out of order pump and didn't realize until I had gotten out. I went to restart and it struggled and whined. Pulled the key - put it back in let the glow plugs light up and it started.

Went to work for the day and when I went to go home in the afternoon I had a dead battery. Got a jump and made it home fine. After my 25-mile trip home I tried to start it and it was pretty dead.

I could be wrong but I didn't think a battery would go south like lickedy split. I have always experienced more of a slow death.

I thought maybe something was draining it maybe, but I don't know for sure. I did upgrade my fuses just several days before with some new copper tipped ones from Mercedes source and changed my interior lights to xenon bulbs (which look nice by the way) but that was it.

I have the stock radio, which sounds like crap, so I don't even listen to that, my buzzers all work so I know I left no lights on... Basically that is how I figured the battery wasn’t charging.

Well, I was going to order it from **************.com but I ended up paying a few bucks more so that I could get it yesterday (car crapped out on Friday) at Comet (local shop)

Of course now i am having a hell of a time getting the new one in there. Is there a trick to it? The new one looks different, but the brushes and holes line up – so I don’t know.

Do the new alts come with the VR already on them?

If I can’t get this thing in there and have to pull the alt anyway, it may be worth it to me to just buy a new or remanufactured Bosch. This car is my daily driver and it’s a pain in the butt to have it not running and having to go back and forth to multiple parts stores in search of random parts that don’t fit.

Also, any one hazard a guess as to what I should pay should I have it installed at and indy vs. a dealer?

I would rather do it my self, I have replaced alts in my old American cars, so I assume it should be a pain in the tail, but pretty straight forward.

__________________
1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Lofat,
Please post whatever results you get if you could. I'm currently having the same problem. Took it to a mechanic with a voltmeter(?) and he said the alt was putting out charge, and the battery was bad. Put a new one in, and about a week and a few days later, it's dead too. Obviously the mechanic didn't know what was up, but I looked at the voltmeter and it seemed like what he was saying was making sense. I wonder if there are any obvious places for a short? I have a new alt. but it looks different from yours. I'm going to try the voltage regulator.
Will

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84 300TD 4 speed, green

Um.... your brush fell out of the regulator connection. That's not good. It should be connected (solder usually) to be able to charge.

Replace the volt reg and you should be good.

I recently got me another alt sans regulator so I could have the double V-pulley alone... mine was replaced without it. I'll be ya if I throw a regulator on it, it too will work.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

ha
i replaced my batery too...my car was fine for 2-3 weeks then the light on the dash came back.. do did the radio noise polution...(btw do you have any radio noise ? when you hit the "gas" pedal does it makes the radio play your engine noise?)
I had that
Firts i replaced my Vr (bought from the dealer).. no luck..Replaced my alternator with a rebuilt one from a local rebuilter shop and everything is A1
btw my alternator doesn't have any VR anymore

To use the multimeter is dead easy just put it on V ( they have like 20 or 12 v mark)
Put the red cable on the + of the batery and black one on the - of the batery.
1-Take a reading with the engine shut (12.15 12.50V is okay.. )
Start the engine and take a reading again (13.5v and higher u're okay
...wait for 2-3 minutes and rev it up and look at the readings..anything bigger then 12.5-13 is okay..

Put on everything that uses electricity and take a reading again.. should be above 12V...

Have Fun

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2001 Jetta TDI .205 injectors + Upsolute "Fast car"
1983 MB 300 SD "Ze Panzer" SOLD
1997 MB 230 C

maybe it is the wrong one.. I am assuming that my alt if not the original - so that adds a whole new dynamic to finding the right VR

I thought at first that the changes were more cosmetic - but now I think maybe not.

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__________________
1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

BTW - thanks again for all the replies - firstly for the info, and secondly because I know people feel my pain -

__________________
1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

you may need a heavy duty alt, especially with a pending wvo system coming. do a search on 115 amp alt. I find them in the yards quite often here and sell what I can find after bench testing and a clean up.

? really? is it internal? Did all MB's stop using a VR at some point - Intereting.

If I could just get this new VR to fit - I would be happy.

Not enough sun left to go climbing under the car again today - so it looks like I am driving the truck again tomorrow... fricken aye - no fun. my tags are expired pending my smog certificate (paid registration & have ins - just that last detail to tend to)

__________________
1979 Thistle Green 300D 272,xxx miles
1984 Orient Red 300 D 4 spd Euro Import - 189,xxx miles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Lofat Productions
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -