Principles of Operation
PRINCIPLES OF OPERATIONThe smart junction box (SJB) monitors the headlamp switch position by sending a voltage reference signal to the headlamp switch. When the fog lamp switch is engaged, the voltage reference signal is routed to ground.
When the low beam headlamps are on and the SJB receives an input from the headlamp switch indicating a request for the fog lamps, the SJB provides voltage to the fog lamp relay. When the fog lamp relay is energized, voltage is routed to the fog lamps.