Better get a voltmeter and do a basic voltage test....

Might be a silly question but : ? did you take the time to clean the battery cables and posts yet ? .

I find most charging system issues include resistance at the battery to cable connection, I always remove the battery from the car and wash it well with soapy water then wash the cable ends in dilute baking soda and water until they stop fizzing .

A simple thing that few grasp the importance of .

If the voltage at the battery doesn't reach at least 12.5 volts with the headlights on when you rev. the engine a little bit look at the connections, sometimes the little wire bail that holds the plug into the back of the alternator gets lost or isn't properly fitted and the plug wiggles loose from vibration .

? Did the replacement alternator come with a pulley ? and if so, where did you buy it ? .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better