I STOPPED ENGINE AT MY HOUSE, LEFT HEADLIGHTS ON TO SEE. WIRING HARNESS FAILURE (DEAD SHORT) IGNITED THE LEFT HEADLIGHT ASSEMBLY, FLAMES EXTENDED OVER A FOOT HIGH. FUSE NEVER BLEW OUT. HAD A FIRE EXTINGUISHER AT HAND, PUT OUT FLAMES. $4600 DAMAGE, BUT SAVED THE VEHICLE. WHY DIDN'T THE FUSE BLOW? I HAVE ALL OF THE DAMAGED PARTS: WIRE HARNESS, HEADLIGHT, BRACKET. TOOK VEHICLE TO FORD DEALER, DAMAGE WAS REPAIRED, INSURANCE PAID. *TR