Heated Glass Element: Description and Operation

The heated rear window system is powered by circuit A4 from fuse 5 in the Power Distribution Center (PDC). Circuit A4 is HOT at all times.

In the RUN position, the ignition switch connects circuit A2 from fuse 2 in the PDC with circuit A22. Circuit A22 connects to the fuse block bus bar that powers circuit F20 through fuse 6. Circuit F2O supplies battery voltage for the timer circuitry inside the heated rear window switch. Circuit Z1 provides ground for timer circuitry.

When the operator presses the heated rear window switch, contacts internal to the switch close to start the timer. Circuit A4 also connects to circuit C 15 at this time. When the switch is released, the timer circuitry keeps the relay energized for the specified time.

Current flows to the heated rear window grid from the switch on circuit C15. The grid consists of two bus bars and grid lines that form a parallel circuit. When current flows through the grid, the grid lines heat up and transfer the heat to the rear window.

Circuit X2 supplies ground for the heated rear window grid. Circuit X2 terminates at the center inside of the rear door below the window.

When the system is in operation, a Light Emitting Diode (LED) located in the switch, indicates to the operator that the system is functioning. Also, when the headlamp switch is in the PARK or ON position, circuit E2 supplies battery voltage to the illumination lamp. When the headlamp switch is in the ON or PARK position, circuit E1 supplies voltage to circuit E2 through fuse 20 in the fuse block.