I agree with Donald regarding alternators, I think.
I definitely think that buying a rebuilt alternator for your Benz from your neighborhood auto supply is a waste of money. I don't, however, buy them from Benz. I have had great success with Bosch certified rebuilt alternators and starters.
You won't go wrong with Donald's suggestion, but I think the Bosch certified rebuilt will also get the job done.
Everyone have a great day,