Why is there a Heater Fan Problem on my Mercedes 190E 1992?

Did not see a place to describe the problem, so I will do so here.

The heater/air fan stoped working, although heat and cold still are felt out of the vents. I found that there is a remote fuse box containing only two fuses. I changed one that was burned out (taged blue) and the other one was missing (tagged white) that I also decided to replace. The fan worked on MAx setting only but would shut off within seconds. i continued messing with it and it stopped again. Assuming the fuse went again. There is a noise in the fan since I bout the car like something was stuck and obstructing the fan. Would that be enough to cause a fuse to blow? Any other suggestions, shorts, etc and how to isolate and fix the problem would be much appreciated.