Okay, sorry to rez this topic, but I got a reply from the mercedesshop guys that pointed me to this http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=21R130L9521R130UKN&year=1984&make=MB&model=300-DT-001&category=All&part=Heater+Temp+Sensor

I think I got the wrong part. Is this correct?
It definitely does not go where the old one went.