The fan on my 300D often takes forever to turn on (often 10 to 30 minutes) when the climate control is on the "economy" ("EC") mode. There is no airflow at all until it starts. Is it the climate control dash unit? the vacuums? (the blower motor was replaced a few months ago at GREAT expense!)

Welcome to Benzforum. Does the fan work in all the other modes on the climate control, such as Defrost, A/C, etc.? Also, can you hear the fan running, but no air coming out of the vents? A very inexpensive item to check also might be the fuse(possible corrosion).

The fan does work in the other modes (much better, actually). Also, air does come out of the vents whenever the fan is running. My worry is that it's the unit itself (with the buttons).