I have replaced the alternator again (warranty replacement from O'Riellys) and the symptoms are exactly the same. I also drove the car on the highway for about 1/2 hour to see if the symptoms went away. Still the same.
From the wiring diagram it sure looks like the "D+" output from the alternator is not sufficient to "out" the antilock light. But shouldn't I still get the "charge indicator" and "brake wear indicator" lights to come on with the ingnition switch on if there is a complete connection to ground through the alternator?
Could both alternators be bad?
1990 Mercedes 300SE (147,000)
1985 Mercedes 300SD (203,000)
1983 Mercedes 240D (167,000)