You might want to verify this before trying(not sure of older cars), but most window motors are of the reversing polarity type and have 2 wires going to them. If you wanted to test just the motor, grab your handy dandy 12v drill battery and cut the wires going to motor and touch them to the drill battery. If you reverse the wires the motor should move in the opposite direction.
The 12v drill battery can be replaced with 18ga wires jumped off of your battery, Dont forget to rig up a fuse inline with the positive lead incase you motor is bad, it will just pop the fuse.