Heated Glass Element: Description and Operation

CIRCUIT OPERATION
The heated rear window system uses a relay located internal to the A/C-Heater, or ATC, control. Circuity internal to the control provides the power and ground for the coil side of the relay. Power for the contact side of the relay is provided by circuit A4. This circuit originates at the battery positive terminal and is protected by a fusible link.

When the operator presses the switch in the control the contacts in the relay CLOSE connecting circuits A4 and C15. The C15 circuit connects from the control to the heated rear window grid. Circuit C15 also splices and provides power for the heated mirrors.

The heated rear window 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. Ground for the grid is provided on circuit Z1 and terminates at the right rear wheel well.