I have a 1981 300D. A few weeks ago the charge indicator light came on, so I replaced the voltage regulator (thanks for the plastic tie), and the light went off. Two weeks later I was driving with the windows down, and heard an unfamiliar metallic noise coming from the engine. The sound is coming from the front - near the alternator and water pump area. Per your advice I poured water over the belts and...the noise stopped. I sighed in relief, until I noticed that the belt had slipped on the alternator, which had stopped spinning. When the belt caught again, and the alternator started to spin, the noise returned - it's a grinding sound. This sounds like I need a new alternator, but I'm hoping that's not the case. Any ideas on what else I could do to try and isolate the noise further? If I do need a new alternator, is that something a novice could install? Thanks!