That depends on the car, they are not all in the same place on every vehicle.
I am no expert; but, according to my Montana repair manual, the blower motor resistor is located under the dash on the passenger side. It can be accessed from inside the car. It's located behind the fan motor
Blower fan resistor controls electric current to the fan motor to maintain different speeds.
pass side under dash
Replace the blower motor resistor block. It is located under the dash on the passenger side.
Blower Motor Resistor is located under the hood on the fire wall behind the right valve cover and the heater hose. It's about the size of a deck of playing cards.
One can purchase a blower motor resistor either in car part shops, like Autozone. Alternatively, one can try looking in eBay for cheaper blower motor resistors.
where is resistor pack on 2010 impala lt 6 cylinder 3.5 motor
it needs a new blower motor resistor ....
under the glove box/dash (passanger side of car). It is right next to the blower motor and has a wire harness plugged in to it. It is held in place by 2 screws
Heater motor switch and or the connection at the switch is melted. Also check connections at the blower motor and blower motor resistor for melt down damage.
Many are in the air duct near the blower motor.
You could have a bad blower motor or there is a resistor inside the blower motor housing which is located under the glove box on passenger side of car (where your feet would go) That could be your problem.