1994 FORD EXPLORER HAD SMOKE COMING OUT OF THE AIR-CONDITIONER VENTS INTO THE PASSENGER COMPARTMENT, SLIGHT AT FIRST, THEN SO HEAVY THAT FORWARD VISIBILITY WAS OBSCURED. AFTER STOPPING THE VEHICLE, A SMALL FIRE WAS SEEN BURNING THE PLASTIC EVAPORATOR COVER WHERE THE BLOWER MOTOR RESISTOR ASSEMBLY IS MOUNTED IN THE EVAPORATOR COVER. SOME SNOW THROWN ON THE FIRE PUT IT OUT. THE BLOWER MOTOR APPEARS TO BE SHORTED OR MAYBE JAMMED FROM ROTATING, CAUSING THE RESISTOR TO GET HOTTER THAN NORMAL, IGNITING THE PLASTIC COVER. MAYBE LEAVES OR OTHER FLAMMABLE DEBRIS CONTACTED THE RESISTOR, BUT I CAN'T TELL AS THE FLAMES BURNED UP ANYTHING IN THE AREA AROUND THE RESISTOR ASSEMBLY. FORTUNATELY, I WAS ABLE TO BRING THE VEHICLE TO A SAFE STOP, IN SPITE OF VERY LIMITED VISIBILITY IN THE HEAVY SMOKE. I WAS ON A SLOW SPEED, LOW TRAFFIC CITY STREET. THE RESULTS WOULD HAVE BEEN MUCH WORSE IF THE FIRE OCCURRED AT HIGHWAY SPEEDS. THE BLOWER MOTOR WILL BE AVAILABLE FOR INSPECTION WHEN I REMOVE AND REPLACE IT TO TRY AND GET THE AIR SYSTEM WORKING FOR HEAT AT LEAST. *TR