I have done this to my 2004 E350 Ford. I am not sure what years this applies to but since a previous question in the forum prompted me to do this I thought I should post my fix. I get my wiring diagrams from
www.alldatadiy.com. They do charge a fee for yearly access but they have a wealth of info on your vehicle.
To get to the DRL you have to remove a plastic cover on the front. It essentially is two bolts for air cleaner and four connectors for that attach the panel to the body.
I then removed the grill witch take three screws on the top and three clips on the bottom.
To clear the way further I removed the whole front end mounting bracket. First I had to remove signal lamps and headlights. The signal lamps take two torx screws, while the headlights remove with some sliding clips. The bracket was removed by eight screws as seen in the picture.
I decided to run the wire back to a switch in the dash to enable myself to turn off the DRL when they are not needed. I found that the fancy rear view mirror that gives temperature and direction had a temperature sensor installed up front, this then already some wire loom going through the to the inside of the van.
I cut the LB/PK wire and spliced in my own wire, I chose to terminate the wire here, and run my switch back to the fuse panel. I could have chose to run have just spiced into the wire and ran two wires back to the switch.
The splices and terminated wire were covered with adhesive lined heat shrink.
I wrapped my wire in the Ford wire harness over to where the temperature sensor was and then entered that wire loom.
This is where the wire comes through the floor board.
I chose to mount my switch close to the existing headlight switch.
To do this I had to remove the dash panel, first you have to take off the knob for the headlight switch, you the remove two screws that are on the top of the instrument panel. You will have disconnect the 12 volt outlets and remove the radio also.
I found an area close to the light switch and drilled a hole in the panel and installed the switch. My switch had three terminals hot, switched and ground for LED. After reinstalling the dash panel I hooked up the switch. I used a piggyback fuse holder a seen in the next picture.
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This was then plugged into the fuse block at F2.15 which is the same circuit the original wire cam from and of course a ground was attached for led
Greg