My 99 XP XLT does not come with factory DRL, so I made my fog-lights to act as my DRL. I did some research here and on other forums and I finally got around doing it. Not only do I have Daytime Running Ligts now, restriction of fog-lights operation on Headlight LOW only is now a thing of the past - I can have it on even on HIGH, on PARK only, and as the primary reason for this MOD, by itself as DRL.

I basically used Chris Coleman's article "Converting Your Expedition or F150 Lighting System to Utilize Daytime Running Lights" as my guide (look for it under ARTICLE above).

NOTE: On my researched prior to trying this MOD, I found out that apparently, '00 Expedition and up may have different Head Light Switch wiring as well as how the switch panel can be removed - so the article mentioned may not apply to those vehicle. I'm not sure about 97 and 98 models, you may want to do some digging to see if it's the same as 99.

Relative to the article, I did a couple of different things which in some ways made it easier:

1) My switched-power source comes fuse box instead of from heater/radio control panel. I used Littelfuse MINI Add-A-Circuit (FHM200BP) and used #25 slot to accomplish this.
2) I put the switch to connect the ground, instead of to connect the 'hot' side of the circuit - that is, the yellow wire is where I tapped my switch, instead of the blk/white wire.

Basically, materials I used are: a simple SPST 15A switch, the Add-A-Circuit, a couple of 1-1/2' #16 wires, a piece of scrap aluminum L-Bar which I used to install my switch under the dash on driver side, and a couple of plastic ties. Instead of splicing the wires (the yellow and the blk/wht wires), I found a way to directly connect the wirings to the terminals by pulling the wires' terminal out of the plastic sockets. I believe there are available connectors that can be used to tap directly to a wire without splicing, but I just didn't want to go out to get them when I'm already working on my project. If one could plan ahead, this is something to consider to get while shopping for materials, should make installation even easier.

Electrical Tape and Multi-tester can be handy, and a drill. Connectors could be handy as well (butt-connector, or plastic screw-type connector).

The metal frame under the dash-driver side is a good place to install the switch via the little piece of L-Bar, and a good source of grounding as well.
Features of this MOD other than mentioned bypass of restriction above are:
- ability to turn off the fog-light/DRL when desired if a switch is installed (higly recommended)
- illuminates fog-light indicator next to the headlight switch which means the switch to buy need not be the lighted kind
- when Add-A-Circuit is connected to a 'switched' source, the fog-light/DRL will be off when ignition is off, which means no danger of draining your battery even if you leave the installed fog-light/DRL switch in 'on' position all the time
- the fog-light/DRL circuit will have a fuse for safety


I actually found a wiring diagram on F-150 forum that applied to 99 Expedition, which gave me confidence that yellow and blk/wht wires are the wires to use as mentioned in the article. Check for 97 and 98 before attempting.

Good luck if you're planning to do it...

Next on my list: Billet gauge with polished rings that I ordered @eBay. This I will do because I'm trying to capitalize on my plan to fix the pesky now-you-see-now-you-don't odometer.