The daytime running lamps (DRL) on a 1999 Ford Explorer are designed to make the truck more visible to other drivers during daytime hours. The increased conspicuity of daytime running lamps statistically reduces the number of accidents that occur. On the Explorer, instead of having separate lamps dedicated to running during the daytime, the DRL circuit provides reduced voltage to the low-beam headlamps, illuminating them with approximately 50 percent of normal power. The daytime running lamps are an important safety feature and should only be disabled in order to test the system or to make necessary repairs. Disabling the DRL system will also disable the fog lights, if the Explorer is so equipped.
Shut down the engine and place the truck's gear selector into the "P" position. Engage the emergency brake and open the hood.
Locate the under-hood relay center on the left side of the engine bay, next to the fender.
Remove the cover from the relay center. Look at the diagram on the opposite side of the relay center cover in order to determine the DRL relay location.
Find and remove the DRL relay from the relay center. Set it aside.
Replace the relay center cover and start the engine. Verify that the daytime running lamps are not operational.
