Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The smart junction box (SJB) receives voltage from the battery junction box (BJB) through circuit 54 (LG/YE). The SJB sends a reference signal to the multifunction switch through circuit 12 (LG/BK). When the multifunction switch is switched to the HIGH BEAM position, the voltage signal is routed to ground through circuit 570 (BK/WH). When the SJB detects the multifunction switch in the headlamps ON and in the HIGH BEAM position, the SJB sends voltage to the high beam headlamps.