Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The smart junction box (SJB) sends a voltage reference signal to the headlamp switch through circuit 1406 (YE/LG). When the fog lamp switch is engaged, the signal is routed to ground. When the SJB detects a request for the fog lamps, the SJB provides voltage to the fog lamp relay coil through circuit 1347 (DB/WH) and the fog lamp on indicator through circuit 1407 (LB/OG). When the fog lamp relay is energized, voltage is routed to the fog lamps through circuit 1776 (TN/OG).