DOUBLE K IS RECALLING CERTAIN BUSES EQUIPPED WITH TRANS AIR TA 73 EVAPORATORS. THE EVAPORATOR UTILIZES A POWER RESISTOR TO REGULATE BLOWER SPEED. SHOULD A SHORT OCCUR IN THE "LOW OR MEDIUM SPEED" CIRCUIT WHILE THE BLOWER IS IN HIGH SPEED, THE SHORT WILL CAUSE THE SUPPLY VOLTAGE TO FEEDBACK THROUGH THE RESISTOR TO GROUND, NOT DRAWING ENOUGH CURRENT TO TRIP THE FUSE.
RiskTHIS WOULD CAUSE THE RESISTOR TEMPERATURE TO RISE TO A POINT WHERE IT WILL MELT AND POSSIBLY IGNITE THE PLASTIC BLOWER HOUSING TO WHICH IT IS MOUNTED. THE OVERHEATING CAN RESULT IN A FIRE.
FixDOUBLE K IN COOPERATION WITH TRANS AIR WILL INSTALL A THERMAL SHUTDOWN DEVICE IN SERIES WITH THE SPEED RESISTORS. THIS SERVICE WILL BE PERFORMED FREE OF CHARGE. THE SAFETY RECALL BEGAN DURING FEBRUARY 2011. OWNERS MAY CONTACT TRANS AIR WARRANTY AND SERVICE CENTER AT 1-800-673-2446 AND DOUBLE K AT 1-715-478-5090.