You need to replace blower motor resistor.
No such part exists
should be the connector in the ac housing closest to the blower motor
The resistor is under the passenger dash just left of the blower motor
It is under the dash, behind the glove box.
With great difficulty!
The blower motor speed resistor is burned out.
That's too bad
Blower resistor. I have an 04 that does the same thing. Bad connection between the resistor and the plug for me. Big topic though for durango those resistors.
Your truck has both. the resistor is between the switch & blower.thje resistor controls the blower speed
it is accesible under the wiper cowl cover on the right side
Mine measures 0.5, 1.0 and 2.0 ohms
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.