2002 Ford Explorer driver side window

Remove the door card and use a volt meter or a test light to check for power at the motor. If you have power in both switch positions, then replace the motor. If you are using a volt meter, one direction will read negative voltage, which is normal. If you do not have voltage present, start looking at the switch. Check for proper operation of the switch and if that is ok, you may have a broken wire. If it's a wire problem, they are common to break at the door jamb. Post back with what you find or any other questions you may have.