behind the battery behind black plastic rain cover...

you have the classic symptoms of a bad Over Voltage Protection relay...
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1FX0MB1RS1OG10UBFB&year=1992&make=MB&model=190-E-005&category=P&part=Overload+Relay


If your lucky the 10amp fuse on top is blown... otherwise replace it and you should be good...

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/showpost.php?p=831799&postcount=13
http://www.peachparts.com/shopforum/showpost.php?p=831807&postcount=14