According to a wiring diagram, there is a Resistor wire or resistor in the leads from a connector (Red/Black) that feeds the Blower motor. If that's a fuse holder in the image, then look further into the wiring to the motor. Could have a problem with the motor and the fuse was overload protection against a failing motor. Most blower motor circuits have a Variable resistor to allow for the fan speed changes at the switch position.