No such part exists
The blower motor speed resistor is burned out.
Your truck has both. the resistor is between the switch & blower.thje resistor controls the blower speed
The resistor is under the passenger dash just left of the blower motor
should be the connector in the ac housing closest to the blower motor
It is under the dash, behind the glove box.
You need to replace blower motor resistor.
That's too bad
replace the blower motor switch
either the control head is bad or there is a blower motor resistor that is bad.
it could be a rock or your cars not funny
Short of it is the resistor controls the fan speeds for the blower. Easy to replace and to my knowledge only available through a dealer.
Failed blower motor, resistor or switch.