Where is the fuse for AC blower fan

The fuse for the Sprinter is in the fuse box on the inside of the panel on the left end of the dash. If you look inside the fuse box cover there is a diagram of the fuse box and what component corresponds to which fuse.

Make sure you get the orientation of the diagram right as they can be confusing because sometimes they are meant to be heals facing towards you to line up with the fuse box layout and sometimes it is a mirror image. Look for the spare fuses which can be found next the the fuse puller, which is another good orientation point.