The fan should show in the diagram as a circle with an "M" inside - signifying a motor. Trace out the line from the thermo switch and it will lead you through a relay (possibly a 5 pin) and out to a circle M.
Keep in mind there are several circle M's; fuel pump, blower motor, starter just to name a few.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.