95 E 320 compressor kicks on and cycles and is ice cold when set to "normal" and "bilevel" settings. However, using the fan control buttons pressed in any of the three positions, no fan is heard, no air flo is felt. When the function button is set to "EC" the servo motors operate and air flows through the ducts only relative to the speed of the vehicle but still no fan. The fan had been making some grumbling noises on "Minimum" setting this winter with the heat on. Is it most likely the fan motor or the fan control buttons? If it's the motor, is there anything unique/unusual about its replacement that I should know? In advance, Thank You.