Circuit Operation

The Heated Rear Window system is powered by a 30 Amp maxi fuse located in the Power Distribution Center (PDC) on circuit A4. This circuit is HOT at all times, The system is also powered by a 10 Amp fuse located in cavity 8 of the fuse block. This fuse is HOT in the RUN position only.

When the operator presses the Heated Rear Window switch, contacts internal to the switch close, and the timer starts. When the switch is released, the timer circuitry keeps the relay energized for the specified time.

Current flows through the switch on the A4 circuit to the C15 circuit, and then to the Heated Rear Window Grid. 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.

Grounding for the Heated Rear Window switch is provided on the Z2 circuit, and terminates at the instrument panel right center support. The grid uses the grounding point at the rear body in the right wheel house.

When the system is in operation, an LED located in the switch, indicates to the operator that the system is functioning. The switch is also illuminated when the headlamp switch is in the PARK or ON position. Power for the illumination circuit comes from the 4 Amp fuse, located in cavity 12 of the fuse block, on the E2 circuit.