Bad ground or short. Check to make sure a smaller than required fuse has not been installed. Use to correct fuse, no smaller or larger. Blower motor can also be going bad causing it to blow a fuse.
On a 1996 Ford Ranger : The blower motor resistor is in the engine compartment It is below and to the drivers side of the blower motor
It is usually ( at least on a 2000 Ranger) locted on the blower motor housing in the engine compartment.
The fusebox which controls the blower motor is under the hood up by the firewall.
The blower is controlled by the blower switch, blower resistor, and relevant power relay.
If it has separate blower speed controls for the front and rear, it has separate resistors. Blower speed resistors are mounted close to the blower motor it controls for cooling purposes.
On a 1995 Ford Ranger : The heater blower motor is in the ENGINE COMPARTMENT , near the firewall , on the passenger side of the engine
The blower resistor assembly is located on the heater case to the right of the blower motor. - Haynes Repair Manual #36071, 1993-2005 Ford Ranger Pick-ups
Common causes, blower motor resistor, blower motor, wiring or controls
Heater blower resistor is what controls the low medium high speeds...
Not sure about the relay, but there is a blower resistor assembly located on the heater case to the right of the blower motor.
The resistors for the blower moter are located in the path of the air blown from blower motor
When you beat the blower motor, you are probably shaking the blower resister. The resister is what controls the blower speeds and is probably bad or loose.