There may be a cabin filter, but you should still hear the blower running even if the filter is clogged.A mechanic would check for voltage and ground at the blower motor when it does not work.
There is usually more than one fuse for the radio.
in the instrument panel fuse block there will be an AUDIO fuse and an AV fuse. If the radio has an amp there will be an AMP fuse in the under hood fuse block.