Heated Glass Element: Description and Operation

Rear Window Defogger:

Heated Windshield Wiper De-icer:

The electrically heated Rear Window Defogger, Heated Power Side View Mirrors, and Heated Windshield Wiper De-icer is available on NS vehicles.

The Rear Window Defogger system consists of two vertical bus bars linked by a series of grid lines on the inside surface of the rear window. The electrical circuit consists of the rear defogger switch in the HVAC and a relay with timer switch to turn OFF the system after ten minutes. The main feed circuit is protected by fuse one (40 amp) in the Junction Block. The rear defogger switch and relay also activates the heated power side view mirrors and heated windshield wiper de-icer. The HVAC rear defogger switch is protected by fuse ten (10 amp) in the Junction Block. The heated mirror circuit is protected by fuse 12 (10 amp) in the junction block. The heated windshield wiper de-icer circuit is protected by fuse 21 (25 amp) in the Junction Block.

The Heated Windshield Wiper Deicer is also activated when the DEFROST mode is selected on the HVAC. In the DEFROST mode the rear defogger relay/timer is bypassed, the heated windshield wiper de-icer will stay ON until the another mode is selected.

CAUTION: Since grid lines can be damaged or scraped off with sharp instruments, care should be taken in cleaning the glass or removing foreign materials, decals or stickers. Normal glass cleaning solvents or hot water used with rags or toweling is recommended.

HEATED WINDOW CIRCUIT OPERATION
The rear window defogger system uses a relay located in the junction block. This relay is protected by two fuses and controlled by the HVAC control. When the operator pushes the ON switch for the rear window defogger, a signal is sent to the HVAC control and the control supplies a ground path for circuit C14.

This causes the coil side of the relay to energize, connecting circuit A4 to circuits C15, and C16. The C16 circuit is protected by a 10 Amp fuse located in cavity 12 of the junction block, and used to supply power for the power mirror heaters.

The F20 circuit that is used to power the coil side of the relay is protected by a 10 Amp fuse located in cavity 12 of the junction block and is HOT in the RUN position only

The A4 circuit, which is used to supply power to the contact side of the relay, is protected by a 40 Amp fuse located in cavity 1 of the Power Distribution Center (PDC) and HOT at all times.

Circuit C15 connects from the relay to the rear window defogger grid. Ground for the grid is supplied on circuit Z1, and terminates at the liftgate ground.

The rear window defogger 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 window.

When the system is in operation a Light Emitting Diode (LED) located in the A/C-Heater control is illuminated.

HEATED MIRROR CIRCUIT OPERATION
The mirrors are also equipped with heating elements. These elements are activated when the operator has turned ON the heated rear window. Circuit C16 provides power for the heaters.

The heated mirrors and heated rear window switch are protected by a 10 Amp fuse located in the junction block cavity 12. Grounding for the mirror heaters is provided on the Z1 circuit and terminates at the instrument panel left side cowl.