Power Window Switch, Left Front
When the ignition switch is in the RUN position, battery voltage is applied to the left front power window switch through CKT 141. The switch assembly is grounded through CKT 550. When any left front power window switch UP switch (not associated with express down) is operated, battery voltage is applied to the window motor. The motor is grounded through the DOWN contact in the left front power window switch. The DOWN contact runs the motor in order to drive the window up.
When the left front power window switch DOWN switch is operated, battery voltage is applied to the window motor in the opposite direction. The motor is grounded through the UP contact in the left front power window switch. The UP contact runs the motor in order to drive the window down.
Express Down Feature (Left Front Only)
When the switch for the left front window is pressed past the first detent in the DOWN position, the express down circuit within the left front power window switch engages. This action causes the circuit to apply voltage to CKT 1136. The left front window moves to the fully open position. When the left front window reaches the mechanical limit, the current draw to this motor increases significantly. The express down circuitry, in the left front power window switch, senses this current draw and removes power to the window motor.
Passenger Windows
The passenger window switches are tied in a series circuit to the left front power window switch. At rest, each switch contact is tied to ground through the left front power window switch. When the master switch operates a passenger window, battery voltage is applied to one side of the associated rear window motor. The motor drives the window in the corresponding direction.
When a passenger window switch is operated, battery voltage is applied to the passenger window motor through CKT 1307. The motor drives the window in the corresponding direction.
The lockout switch, which is incorporated in the left front power window switch, controls the voltage on CKT 1307. When the lockout switch is engaged, battery voltage to CKT 1307 and the passenger window switches is interrupted. This function allows driver control when the passenger window switches are operational.
Each motor is protected by a built-in electronic circuit breaker (PTC). The PTC resistance increases under the following conditions:
| • | If a window switch is held too long with the window obstructed |
| • | After the window is fully up |
| • | After the window is fully down |
The resistance returns to normal after the voltage is removed from the motor terminals.
