Welcome to the list!
It'd help to have a little info about the vehicle: which model, year, mileage . . .
My very limited knowledge in this area is that there are some models with known problems with increasing current draw (and thus blown fuses) in blower motors as they age. I believe there is a factory-approved fix which entails increasing the fuse size -- but please do a search on this before you just put in a bigger fuse.