They probably did the TSB whereby they install an inline fusible link for your radiator fans. The fans are known to seize, causing the wiring to overheat and start a fire. By installing the fusible link, it will open the circuit b4 the wiring gets too hot.
Now, this also means that should this happen after you are out of warranty, Ford will not replace the defective fans. You will have to pay to fix an obvious manufacturer defect. This is how Ford loses customers permanently, by taking the cheap route to fix a factory defect. I can think of a few others (Front Coil Springs, anyone??? :rolleyes: ).