Grand Marquis V8-281 4.6L SOHC (1992)
Daytime Running Lamp Control Unit: Description and Operation
The Daytime Running Lamps (DRL) System operates the vehicle's Hi Beam Headlamps at reduced power during the daytime to make the vehicle more
visible to other drivers.
With the Ignition Switch in RUN, the park brake released and the headlamps turned OFF, the DRL Module outputs a pulsing voltage at pin 8 to operate
the Hi Beam Headlamps at reduced intensity. When the DRL System is operating, the Hi Beam Indicator is not illuminated.
Applying the park brake or turning on the Headlamps disables the DRL System. Applying the park brake grounds pin 6 of the DRL Module. Turning on
the Headlamps in the low beam position applies battery voltage to pin 7 of the Module (and removes the ground input that the DRL Module senses
through the Lo Beam Headlamps). Turning on the Headlamps in the high beam position applies 12 volts to pin 8 of the DRL Module.
The diode shown inside the DRL Module prevents low brake fluid level from disabling the DRL System.
The DRL System is used only on vehicles sold in Canada.
NOTE: The headlamps may flicker during engine start-up and shutdown on DRL-equipped vehicles if the A/C-Heater Blower Motor is turned ON. This
is a normal condition.
Also, during Lo Beam Headlamp operation on a DRL-equipped vehicle, the Hi Beam Indicator will not illuminate when using the flash-to-pass feature.
