Auto body motor modules enable many of the luxuries found in modern automobiles. Motor modules consists of a gear train and an electric motor, usually packaged in a shared housing, and are used to drive a geared lever or pulley system that in turn moves a mechanical accessory, like a window, car seat, or sun-roof. This application note uses a window regulator to illustrate the interaction between the mechanical assemblies of the regulator and their impact on the magnet and Hall-effect sensors used to monitor the motor in the regulator.