It should be two screws up under the inside cab on the passenger side, below the glove box area with a wiring harness connected to it.
Replace the blower motor also.
Remove the HVAC rear module auxiliary assembly.Disconnect the electrical connectors from the rear blower resister auxiliary.Remove the air outlet duct from the rear blower motor controller auxiliary.Remove the screws from the blower motor rear resister auxiliary.Remove the rear blower motor resister auxiliary.Replace the resister and install new thermal gasket.................
Replace the resister, if that doesn't work replace the blower motor.
Replace the blower motor speed resister.
when motor stops, tap on motor and see if restarts. if it does replace motor. there is a bad spot on the armature. if not check the blower resister.
Behind the glove box.
It's close to the 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.
Look at the link I posted, that should help you. (:
location of resister for blower motor on 1997 s 10 blazer
Blower motor resisters are generally mounted nearby the blower motor for cooling purposes.
The resister for the 2001 prism blower motor drops voltage to the blower motor. This is how the blower motor runs at a lower speed.