I OWN A 1996 FORD EXPLORER SPORT 4X4, 4.0 LITER V6 WITH 5 SPEED MANUAL TRANSMISSION. THIS IS A MOTOR MADE IN GERMANY AND THE TRUCK, IN THE LOUISVILLE, KY. FORD PLANT. RODENTS TOOK UP RESIDENCE IN THE HEATING SYSTEM, AND FILLED THE HEATER BLOWER ASSEMBLY AND DUCTING WITH SCAVENGED MATERIALS, WHICH TOOK UP APPROX. 1 CUBIC FOOT OF SPACE, ONCE EXTRACTED. MUCH TO MY BENEFIT, THE MATERIAL JUST SO HAPPENED TO BE FIRE RESISTANT STUFFING FROM MY ARCHERY TARGET, STORED IN THE SAME BUILDING. I STARTED MY VEHICLE AND IMMEDIATELY UPON TURNING ON THE HEATER, I HEARD A TERRIBLE NOISE WHICH ENDED ABRUPTLY. MY HEATER STOPPED WHEN THE NOISE STOPPED. IN AN EFFORT TO DIAGNOSE THE PROBLEM I INSPECTED THE ENGINE COMPARTMENT. I THEN NOTICED A BURNT SMELL, BUT SAW NO SMOKE. UPON REPLACING MY BLOWER MOTOR I INSPECTED THE OLD ONE, WHICH HAS CHARRED REMNANTS OF THE FOREIGN MATERIAL INSIDE AND WRAPPED AROUND THE ELECTRICAL COMPONENTS. THE ONLY OPENING TO THE INNER COMPONENTS OF THE BLOWER MOTOR IS ABOUT 1" IN DIAMETER AND HAS A RUBBER TUBE PLUGGED INTO IT. IT APPEARED UNDISTURBED AND WAS CONNECTED WHEN I FIRST SERVICED IT. I ALSO DISCOVERED AN OPENING ON THE LOWER SIDE OF THE BLOWER FAN HOUSING, NEAR THE FIREWALL. THIS UNOBSTRUCTED OPENING FACILITATED THE RODENTS' ENTRY TO THE HEATING SYSTEM. IT IS OF MY OPINION THIS IS UNSAFE, AND HAD THE FOREIGN MATERIAL NOT BEEN FLAME RESISTANT, I'M CONVINCED MY VEHICLE WOULD HAVE BURNED. I ENTERED MY VIN NUMBER INTO FORD'S OFFICIAL WEB SITE, AND WAS RETURNED ZERO RE