Do you hear the blower motor come on? I think the center vents only work when the A/C is on and the side vents (and vents by your knee) work with the heater and the A/C. Check the fuses, even if they look good (not obviously blown), spin them in place to try and re-establish good contact. Those ceramic type fuses are well known to lose contact as the metal oxidizes.
I was ready to replace the wiper motor in my daughter 190E, when I checked the fuse it looked okay, I spun it and the wiper came on momentarily. It wasn't blown but I couldn't get to make good contact, replaced it and the wiper has worked fine ever since.
Just a suggestion, maybe worth checking.