Be aware that there are 2 fuses ..one feeds the Control Panel and the other is a heavier fuse for the bkower itself. Some chassis have the blower fuse outside the fuse box in an aux fuse holder. .....
There was that mod on your chassis , so it may have been done.
A trick is to put the fan ON defrost, key ON , and then spin the fuses in their holders...if the fan starts as you spin that fuse , you have a problem where the fuse sits in the holder ..Very common w/Benz fuses..they look good, but the holder connection is poor.

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A Dalton