Need help with alternator and battery
 

The adjuster bolt on my alternator is broken supposedly so i cant get my belts to to tight, they are decent, so after i turn my car off it dies. Anyone have advice with that? while driving the battery is fine but if i turn it off for 5 minutes then try to start it, the car dies

Does anyone know if it's replaceable or ANYTHING? I don't want to junk this car over something so small

Of course it's replaceable:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1JU1236H41PU0SB689&year=1982&make=MB&model=300-SD-002&category=F&part=Alternator+Adj.+Bolt


However, unless the alternator belts are not turning, whatsoever, I would suggest that you might have additional problems. You can get the belts sufficiently tight to verify that the alternator is working properly.

The voltage should be about 13.5V or more at 1500 rpm or above.

well the belts do turn and when i turn the car on the voltage goes down then up above 13 v, but when i turn the lights or wipers on then turn the car off after driving for a while the battery dies

Is it very difficult to replace?