Alternator Problem (1983 MB 300D)
 

The dash alternator light was not on when I turned on the ignition key yesterday. I immediately checked the voltage from the alternator. It was not charging at all (12.2 volts which I assume was the battery). The light still was not on. I took the alternator off the car, and it checks out perfectly. This is new to me! Is there a fuseable link? Wiring problem? Any help really appreciated. :mad:

Richard

My alt wasn't charging the system at idle. Then it kept getting worse. I installed a battery float charger on the car and plugged it in everyday. Then with no warning my alt locked up a couple weeks ago and shredded the belts leaving me stranded 400 miles from home. I just upgraded to a 120 amp alt I got off ebay and it's a great improvement! Not sure I can help with your problem, but my alt would charge as long as I was moving, but idle was a no go. Maybe yours is doing the same?

The above in red is to test the Bulbs in the Warning Lights. If the Charging Lignt did not come on but the other Warning Lights did come on there is a good chance the Bulb is no good.

If you don't have the Charging Light Bulb in the Circuit the Alternator is not supposed to charge.

Chances are its a defective alternator/voltage regulator. Chances of it being a bad wire are slim but double check the negative batt cable.

I had this problem, replaced alternator(with comes with a voltage regulator) for $120 and the light did not come on again. These cars on great, they can run without alternator, voltage or belts. I made it home 500KM with none of these and did not overheat... lol. I will never.. ever... ever sell my 240D.