1984 Mercedes 300D. I recently discovered a screeching belt noise sounds last night as I was on the road, it would come and go at first, but then it just got louder and louder as I was driving. I pulled over and turned the headlights off the screeching noise went away on its own when I turned them back on and accelerated it came back. So it seems to me it only happens when the car is under load.

The car has less than 10 months new Alternator/Battery/Water Pump and 2 new belts.


Any ideas?