Because your daytime running lamps use a reduced output of your high beam headlights. The low beam filament on your left headlight is out.
Change your left headlight bulb, and your all set.
If you are referring to the daytime running lamps (DRL) on Canadian Explorers not turning off when the parking brake is engaged, I believe that is a defective DRL module.
The 2008 Ford Explorer's turning circle is 36.8 ft..
The 2005 Ford Explorer's turning circle is 36.8 ft..
The 2013 Ford Explorer's turning circle is 39.2 ft..
The 2001 Ford Explorer's turning circle is 37.3 ft..
The 2014 Ford Explorer's turning circle is 39.2 ft..
The 2002 Ford Explorer's turning circle is 36.7 ft..
The 2004 Ford Explorer's turning circle is 36.8 ft..
The 2007 Ford Explorer's turning circle is 36.8 ft..
The 2009 Ford Explorer's turning circle is 36.8 ft..
The 2012 Ford Explorer's turning circle is 38.9 ft..
The 2006 Ford Explorer's turning circle is 36.8 ft..