I just replaced the voltage regulator on my 1982 300D.

Man, was that thing in need of extraction! The brushes were almost non-existant. I don't know how my battery didn't die. Not only that, but the contact spring was missing entirely.

It was a bit of a pain getting at the screws, I actually had to saw the end of a stubby screwdriver off so that I could have room to untighten the screws (right angle screw couldn't fit past a hard line in the way)....and that was after letting them soak in PB Blaster (thanks to whoever pointed PB out to me on this forum...a gazillion times better than WD40).

Pete.

__________________
Gallery

www.PeteChipmanPhoto.com

In review the past history of my 83 300TDt I saw a receipt for towing, two batteries, then 3 hours of labor, then a charge for a voltage regulator... Seems it was toasting batteries, and the garage (not a benz dealer) couldn't figure out what the problem was, perhaps a volt meter would have told them.
Previous owner did get a refund on one battery btw, along with a note from his secretary that they garage refused to surrender the car to his wife until someone gave a credit card number, guess she was pissed.