Lorenzo7,

It sounds to me like you have either an advanced case of worn alternator brushes (how many miles on the car and have you ever changed them?) or a failed regulator. You may also have some burned out bulbs in your dash panel, or both, with the bulbs the casualty of the voltage regulator failure.

How long did the battery charge take? I am curious. Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

The battery charging was done at an auto parts store. It took about 1hr and their machine showed it to be a 'good' battery holding a full charge.
I checked it myself after that (positive and negative disconnected) and it had 12.04volts and 93mA (this is what the manual shows for proper function).
I live in Houston, it is plenty warm right now- mid 70's F
The alternator was replaced 5 years-30,000miles ago.
I re-connected the battery, disconnected the alternator, and had no loss of charge on the battery (over a 1-1/2hr period).
I re-connected the alternator, and as we have been conversing (about an hour), the battery has gone down to 11.74volts.
I had also posted this on the tech forum and Steve has just responded with a way to test the bulb and rule that out (see the tech forum, same title- charge indicator light).
If I rule out the bulbs I think everyone is in agreement that it is the regulator and brushes.
Thanks again.

In an upset condition there can be a number of peripheral malfunctioning items that make the central issue harder to see. The 80 mA leakage current, for example, may also be the RF filter on the alternator. This thing is a capacitor that is supposed to only conduct alternating current, with the purpose of taking the voltage ripple out of the system. Voltage ripple gives you the engine speed noise on the radio in the car and is generally not a good thing for a DC system. When these fail they can start to short so DC current passes through them and it can take a while for them to become a dead short. It can look like the alternator, but it is really not the alternator, per se. A contributing failure mechanism is a voltage spike from a bad regulator that will help burn through the capacitor.

Anyway, we need more data. I would jump to removing the voltage regulator and inspecting it. Two screws and an electrical plug with a restraining clip. Out it comes and check the brushes. If they are worn to nubs, nice and even, you get a new one for under $50 and put it in and all is fine. If one brush is worn more than the other, it is new alternator time. This is an indication of an imbalance that is either electical or mechanical, and either is is rebuild. FastLane has them, quality rebuilds from Bosch. Like with starters, mechanical rebuilds are not sufficient and unfortunately that is about all the typical rebuild effort consists of, and they don't work right. They need to be rewound and electrically rebuilt as well. Bad diodes in the rectifier section are a leading cause of rapid failures of voltage regulators, including the odd length brushes. As are mechanical problems with bearings.

Anyway, we need data. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Way back in this thread you stated that you were getting 80+ ma across the battery even with it totally disconnected. Hope was just some slip in terminology. But go back and check statements to see if any confusion occured at that point. (maybe i'am confused, would not be first time)Needless to say if you had tried to read current across battery you would have a blown fuse or worse in your meter so i know you did not do that. A lot of guys install aftermarket radios,cd units etc. and only use the inline fuse supplied with them and tie them to some constant hot buss point. Electronics go off with your key? If not
have seen them draw current even when turned off. Developed some kind of internal defect..? You may have been living with a slight additional draw for a long time. I would try to get alternator up and running and then double check for draw later.As the person guiding you has stated by measuring across battery running and not running you will confirm if alternator is functional. Just a thought as i really hate the action grinding to a halt.

HA! You were refering to my post right? Well, I almost panicked when I started my car earlier on and realized the charging light wasn't coming on!! I almost got so angry that I was going to drive back to KC, dump the car and take a more reliable, newer car back here. Then I read your post about checking the bulb. I had just ordered spare bulbs last week from Fastlane two weeks ago so I switched out the bulb and - the charging light came on!! I cooled off and relaxed at that point. Indeed, most of the time the best solution is the simplest one. At this point, can I assume my voltage regulator is good? Also, when they run a test on your alternator, does the functionality of the voltage regulator affect the results they obtain at all?

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1999 Mercedes-Benz S600, 103K miles - garage queen
1988 Mercedes-Benz 560SEL, 89K miles - daily driver
2007 Hyundai Sonata Limited, 31K - daily driver