My driver's side fog light bulb exploded on my '02 HD. There was no evidence of internal moisture. Some of the hot pieces of glass emebdded themselves into the plastic seal around the glass lens.
A couple of tips:
1) The bulbs are easy to replace from under the truck. Firmly rotate the exposed black plastic bulb holder about 30 degrees clockwise.
2) If you want to clean out the loose glass from inside the housing, you can easily remove the light and its bracket as one unit by removing three bolts along the top of the bracket - you need a 5/16" socket. The units are sealed, so the best you can do is shake the glass out of the unit through the hole for the bulb.
3) The front lens is glass and very vulnerable to breaking from rocks etc. Some sort of plasic or wire protectors would be a nice aftermarket product.
4) The replacement bulb is a 55 watt H1 halogen bulb available in most auto parts stores for about $6-7.
5) The exploding bulb released a powdery substance that lightly coated and somewhat clouded the relector. I will see if Ford will cover its replacement under warranty. It looks like an expensive unit.

 

maybe this isn't the "right" thing to do, but i know others have done it and it worked. Push on the fog from the outside and just snap the plastic bracket and unplug the fog and ditch it if its no good (you may want to save that lense though if its still good). then go to the dealer and ask for a replacement. it should be under warranty. Mine snapped (and no, i didn't break it, i still have it though as a spare) and it was hanging under the truck. i unplugged it and took it to the dealer , and since there was no damage to the truck, they replaced the assembly underr warrany and let me keep the old light. quite a few others had the bracket break, or foglight crack and they broke the bracket and gotten it replaced under warranty. will just save ya a few bucks. hope this helps

 

Yep, exactly what Josh said. I really did lose mine. It snapped off somewhere when I was driving. Looked at the front of my truck when I got home and said WTF!! There was absolutely no damage to the valance or anything the bracket just snapped clean.

Took it to the dealer and they replaced under warranty.

Good luck!!

 

jjmiller,

Harley #356 is right! One of my driving light lenses fractured about 2 weeks ago. Found that the Ford replacement only comes as an assembly for about $200. I did what Harley #356 said and snapped it off at the plastic mounting bracket and took it in to the dealer. They replaced it under warranty because they know this to be a sub-par design.

Also found from the dealer that the driving lights break more often from rain than rocks! That's right! ... RAIN! They said that these lights run so hot that when cold rain hits the lights after they have been on for awhile that it cracks the glass. Since you live in Seattle (I live in Woodinville) this can be a REAL problem!

I found a solution though! "Stick-em stuff" like StonGard (or any equivalent) will NOT work because it gets brown from the heat and looks really bad. I have also heard of them cracking even after such installation. The solution I found is to go to Home Depot and by a pair of Malibu Lighting low-voltage halogen house/landscaping plastic flood lights (part # ML25HP2) for $14.95 a pair. They have the same 4.5" diameter lens as the driving light. Take a "blade" and carefully slice/seperate the lens from the "sealed beam" and carefully pry the lens off the rest of the flood. It will snap on right over the glass lens of the driving light. Since the flood lens is convex, it provides about 3/8" of "dead air" insulation from the glass so it will not melt or discolor. Since it is a "flood", it diffuses the light a little but not noticeable (unless you are an HID purest) during driving.

 

LeeRandall,
Thanks. I will try installing the covers.