When I press the open button on the keyless remote of my 2003 screw F150, the only lights that blinks or flashes are the two white ones above the rear view window on either side of the third stop light.

How hard or expensive is a conversion to make the head and tail lights flash as does my 2006 Explorer?

 

I'm pretty sure its in the owner's manual, I don't have it saved on this computer though.