The pull down motor switch could be defective. Check for power to the motor
check fuses?
Yes
could be the motor mounts as to it jerking if its not the tranny..
Check the fuses, check the relay and then check the fan motor.
check to see if the window switch of the driver's side is getting power, if you are getting power to the switch and the switch is sending power out to the motor but the motor is not responding the motor needs to be replaced
So whats the question WHY? Could be a bunch of things. How about checking the fuse first.
Built in the fan blower/motor.
if it doesnt work on 1 and 2 it could be a blower motor resistor but if it doesnt work at all check the fuses, relay and check voltage if it reads 12 v replace the motor
your motor needs to be replaced,or it could just be the module on the motor.
You have to drop the subframe
Resistor or blower motor power module.
sounds like a defective blower module