Larry T makes an excellent point about the lack of a voltmeter on a MB or any diesel for that matter.. IF you see less than 10 volts while cranking, you better start checking otherwise you will wind up stranded.
Monitoring a voltmeter will tell you much about the charging system and alert you (usually) to something that is going to happen to your battery system soon. It is easy enough to install a voltmeter. If you do not like the idea of making holes somewhere in the dash, then try a voltmeter that has a cigarette lighter plug on the end of it and plug it into the cigarette lighter inlet. Marshall in Feenix, who onetime got stranded for the same reason way up in the foothills of the Sierra Madre Mountains
