We're talking about an '85 300D, California model. A few days ago, I noticed that the blower was working intermittently, and mostly not at all. So, I removed it, cleaned it, removed and resoldered its amp, and put it back together. Now it works well enough that I have heat and defrost and maybe it is working as it should be. I really never paid all that much attention to it before and the manual is not so detailed as the convoluted mind of Benz's engineers.

Now, the trouble is, I don't know whether what I am observing is correct operation or an anomoly. On defrost and high, the blower starts immediately, which is what I would expect. On low, automatic, and with the heat on any setting other than defrost, there is a delay between my pushing the button and the fan coming on. This delay, which seems quite regular, really confused my diagnostics.

Does anyone among you know the logic behind the blower motor controls?