Normanator

Good afternoon all, last week the SLK stopped blowing air from the vents on the dash below the windshield. Everything else works exactly as it should, just no air from those vents. I have the style controls with the colored wheels and knobs for the fan speed and vents, no auto temp control. I gather it has likely broken the arm connecting the vent diverter flap to the electric motor, but cannot seem to find anything specifying its location under the dash. Would anyone be able to point me in the correct direction so I can pull this apart and get it fixed?
Much appreciated!