Normal Operation

The rear window defrost relay receives power from the BJB fuse 23 (40A) on circuit (B). When the rear window defrost switch is pressed to the ON position, a ground is supplied to the SJB on circuit (DL/O), through the rear window defrost switch, then through circuit (B/W). Then the SJB will activate the rear window defrost relay. The rear window defrost relay then supplies 12 volts to the rear window defrost grid on circuit (BR/LB). The rear window defrost grid is grounded through circuit (B) to ground.