Fog Lamps
WARNING: This page is about a different car, the 2019 Ford SSV Plug-in Hybrid, 2019 Ford Police Responder Hybrid, and 2019 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
System Diagram
Fog Lamps
The BCM monitors the headlamp switch position by sending voltage signals on multiple circuits to the headlamp switch. There is one circuit for each headlamp switch position. At any given time, one of the signal circuits is switched to ground to indicate the headlamp switch position.
When the BCM receives input from the headlamp switch indicating a request for the fog lamps, the BCM provides voltage to the fog lamps.
The BCM also provides an overload protection of the fog lamp output circuits. When an excessive current draw is detected, the BCM disables the affected fog lamp circuit driver.