I have a 78 MB 300D. there is a small black box with a female connector on the back of my alternator. Any idea what this is? I am experiencing a lot of electrical problems. This is the third time I have changed my alternator. New battery and no shortage probs I can see. any Ideas?????

That would be the voltage regulator and if thats gone out then you're electrically screwed until you replace it... the 2 times I've put in a new alternator they've come with new voltage regulators as well so I never really troubleshot it any futher to exhonerate the alternator or voltage regulator. Sometimes changing the alternator and not the VR will work for a short period of time, but they generally die again within a week... month at the most from my experiance. The VR's are cheap, and the last time I got an alternator with a VR it was about $100. Bolted and plugged in and have been rockin and rollin ever since.

Good Luck!

the box he is reffering to is not the regulator, the regulator does not have a female connector. he is however reffering to the condenser, i believe it acts as a noise surpressor, but it is not necessary for the alternator to function. it is mercedes part number 001-156-69-01
where are you getting the alternators? at my shop we only recommend and install bosch remanufactured units the bosch number for your car is a AL 80 X
hope this helps. send me an email if you have more questions. ray
mercedessd@cox.net