300E Alternator

[robi99]

My alternator quit alternating last weekend while I was on vacation. Thanks to a great "parts guy" at a MB dealership, I purchased an alternator at 5:30 PM on a Friday afternoon. They close at 5:00 but I caught him going out the door.
Before looking for somone to install it, I popped the brushes out of the old alternator and they were wasted. I installed the new ones and the charging system is working great.
2 questions as a result of this experience.
1) My charging system red light never came on to warn me of a problem. First indication of a problem was ABS light. The light works. It comes on when key is turned to the run position. Any ideas??
2) The MB dealer is willing to take the alternator back and charge me for only the brushes. My car has 102K miles. Am I going to need a new alternator in the near future or just new brushes in another 100K miles??
Thanks for the help.