UNEXPECTED FIRE UNDER HOOD AFTER TURNING THE DEFROSTER SWITCH ON. WHILE DRIVING IN A PARKING GARAGE MY NEPHEW WHO WAS DRIVING AT THE TIME TURNED THE DEFROSTER SWITCH ON AND ALL OF A SUDDEN THERE WAS SMOKE BELLOWING OUT OF THE VENTS INTO THE FORD RANGER PK/U CAB. HE PULLED OVER TO THE SIDE OF THE LOT AND SOMEONE RAN UP TO HIM AND TOLD HIM TO GET OUT OF THE PK/U BECAUSE HE SAW FIRE COMING FROM UNDER THE HOOD. THE GUY WAS CARRYING A FIRE EXTINGUISHED. HE TOLD MY NEPHEW TO SLOWLY LIFT THE HOOD WHILE HE BEGAN TO EXTINGUISH THE FIRE UNDER THE HOOD. THE FLAMES WHERE VERY INTENSE THAT IT MELTED THE HEATER CORE COVER, WIRING, THE A/C MOTOR AND FAN AND PAINT ON THE INSIDE AND OUT SIDE OF VEHICLE. IT ALSO MELTED THE INSIDE OF THE DASH BOARD WHERE THE ON THE OTHER SIDE WOULD BE YOUR GLOVE COMPARTMENT. IN THE MEANTIME NEPHEW CALLED 911 AND FIRE DEPT WAS DISPATCHED AND THEY GOT THERE FEW MINUTES LATER AND THE FIRE HAD BEEN PUT OUT ALREADY BUT AS A PRECAUTION THEY FOAMED THE CAR ENGINE AND UNHOOKED THE BATTERY. HE WAS TOLD TO NOT START THE TRUCK AGAIN AND HAVE IT FLAT BEDDED TO GARAGE FOR INSPECTION AND POSSIBLE REPAIR. I CALLED FORD AND THEY TOOK REPORT WHICH WILL TAKE 7-10 DAYS TO GET INSPECTOR HERE IN FL TO LOOK AT VEHICLE. THIS WAS A 1993 FORD RANGER, 2 DOOR,STAND BED, 4CYL, MANUAL. THIS TRUCK JUST BURST INTO FLAMES WITH THE ONLY CAUSE THAT MECHANICS HAVE FOUND SO FAR WAS THE MOTOR BURNED FROM THE INSIDE OUT AND HEATED SO MUCH THAT IT MELTED THE BRACKETS HOLDING IN PLACE A