C class used an electric pump, vs the belt driven ones of the E class with 104 engine.
Someone probably disconnected it b/c they are very expensive.

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1W70PZW4N20N0HOQH7&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1995&product=B6010-139652&application=000707704

No idea why they would rewire it to the fans , unless they just wanted something to run that sounded like a pump for emissions test ?????????????

It should be under the alternator, toward the radiator [ or that vicinity]