A lot of the newer cars use motors with plastic gears, then they use a wire cable to raise and lower the window. The problem is the wire cable will begin to eat away at the edges of the plastic pulley that it rides on. When it does the wire usually tangles itself up by slipping off the pulley and looping on itself. You might be able to unravel the wire and then lift the window by making sure the wire is back on the loop as it should be (assuming it's the pulley and not the motor). It will not last long and you will have to replace the motor which is only sold as the "window assembly". You have an older car and I'd check the junk yards if I were you. It shouldn't be too hard to find.