With the ignition switch set in the RUN position, battery voltage is applied to the master switch assembly via CKT 141. The switch assembly is grounded via CKT 150. When you operated any master switch assembly UP switch (not associated with Express Down: refer to the next paragraph), battery voltage is applied to the window motor. The motor is grounded through the DN contact in the master switch assembly. The assembly runs the motor in order to drive the window up.

When you press a master switch assembly DN past the first detent, battery voltage is applied to the window motor in the opposite direction. The motor is grounded through the UP contact in the master switch assembly. The assembly runs the motor in order to drive the window down.

When you press the left front window switch to the first detent in the DN position, the express down circuit within the master switch assembly engages and applies voltage to CKT 165. The left front window moves to the fully open position. When the left front window reaches its mechanical limit, the current draw to this motor increases significantly. The express down circuits in the master switch assembly senses this current draw and removes power to the window motor.

The rear window switches are tied in a series circuit to the master switch assembly. At rest, each switch contact is tied to ground through the master switch assembly. When the master switch is operating a rear window, battery voltage is applied to one side of the associated rear power window motor. The motor drives the window in the corresponding direction.

When you operate a rear window switch, battery voltage is applied to the rear power window motor through CKT 1307. The motor drives the window in the corresponding direction.

Each motor is protected by a built-in electronic circuit breaker (PTC). If a window switch is held too long with the window obstructed, or after the window is fully up or down, the PTC resistance increases. The resistance returns to normal after voltage is removed from the motor terminals.