What year is your truck? Is it still under warranty? If so, and your plastic lenses have heat cracks in them, take it back and have them replaced at Ford's expense.
I had mine replaced after only one year at no charge. They tried to say that they were caused by rock chips but could not explain how the rocks never managed to hit the bumper cover or headlight lenses. The cracks are caused by the heat of the halogen bulbs and is an obvious manufacturing flaw. I refuse to pay for new lenses and will continue to get a new set under warranty every year until the problem is corrected by Ford.
Some say the heat cracks are caused by using the foglamps in wet weather. I'm not buying this theory because my truck is never driven in the rain and I still get the heat cracks.
The halogen bulb just makes too much heat for the plastic lenses, it's that simple. To prove my point, I intentionally refrained from using my foglights for five months after they were replaced under warranty last September. Within a month after I started to use them again, tiny cracks started to appear. Prior to turning on the foglamps again, they continued to look brand new. Now, four months later, both of them are full of cracks.
Ford has to know there is a problem with the lenses on the 2001 and newer Lightnings. If they don't, it's only because other Lightning owners are not forcing the issue on them and are either living with the cracked lenses or replacing them on their own nickel. As long as my truck is under warranty, I have absolutely no intention of paying for new lenses.
I am definately going to be talking to the dealer! They have been less than helpful at times, and I have called the SVT people once as well....to give an example, I took the truck in for them repaint areas THEY scratched by improperly installing a hard top cover on the bed....nobody thought hard enough to clean the inside of the bed before they painted. I spent a week in and out of that damned place getting it done right. But I will be contacting them ASAP!!! THANKS!!!
I currently own two L's - an 01 and an 02. Ken, I will tell you that the dealer owes you a set of lights and Mike, the same. If you have a Lightning under warranty, SVT will replace the lights for you free of charge. Just call them ( www.svt.ford.com ) and tell them about your problem. The SVT certified dealer has NO CHOICE but to honor the repair. Here is my story:
I have a black 01 and I noticed within the first three months of ownership, I had some of those same cracks that did not look like road damage. When I pointed it out to the service advisor at Covert Ford here in Austin, I got the ole, "Oh, those are rocks hitting your lenses." I told them, "So why aren't there any "pock marks" on the rest of my front air dam? Are the rocks magically only hitting my fog lights and then bouncing straight back to the asphalt roads I drive?" I pointed out that rock damage is small, circular, spider web looking marks but these were long cracks like heat was involved. The blew me off and I called SVT. A guy named Matt at SVT told me about the defect and SVT called Covert to confirm and in one week, I had a new set of lights. But.....here's the funny part: The new lamps had noticeably different lenses! The looked clearer and very unlike the first set of lights I had. My 2002 did not have this problem at all so I know it was a run of manufactured lights there were bad from the factory.
Take care and remember: You gotta fight......for your right.....to get parts.
Sorry to stray slightly from the fog light fiasco but....
you mention the Royal Purple. What is that and where can a boy get some? I don't think I have ever seen it around my neighborhood. Thank you for your time and help.