My driver side one works fine, the passenger side only goes left and right, no up and down...i don't even hear the motor when i press it up and down for that side...haven't looked into it as i don't change the vertical view often. Listen to hear if the motors are working, then check the mirror switch connections (easy to do as 5.0 explained).
On my old tempo, it had power mirrors. At one point, one no longer worked. I took it apart and found that there was a "t" shaped pivot that secured the mirror to the frame, and one side had broken...allowing the "screw-like" adjusters to spin freely, while not attached to the glass, and therefore not moving the mirror.