Blower Motor

I have a 1994 Police Package Caprice and when I turn my heat all the way up it makes a loud humming noise, I figured it is the blower motor. does anyone know where the blower motor is located so i can replace it or does anyone have any suggestions on where else the noise is coming from? I live in Chicago so I need my heat on all in the winter but it would be nice to ride and not hear that noise so I'm looking to replace the blower motor, should I?

Its in a big black box on the passenger side fire wall. You should be able to replace it easy.

blower motor for heat is under the dash, at least for my car, -10 + no heat = not fun =)