Yes, you should get low speed fan operation due to pressure at about 250psi (at least thats what the C280 had this week after I put a new fuse in the low speed relay).
You will need to view a wiring diagram to see whats involved (there are many changes by year). It is very likely that you have a fuse or resistor problem.
The switch that is involved is the one on the drier with the short pigtails. The one with no wire is the low/high pressure switch.
Bosch Master, ASE Master, L1
33 years MB technician