United States 98V313000
Blue Bird Body Company
The problem
VEHICLE DESCRIPTION: SCHOOL AND TRANSIT FORWARD AND REAR ENGINE BUSES EQUIPPED WITH CUMMINS ISB AND ISC ENGINES. THE WIRING HARNESS TO THE COMBUSTION AIR INTAKE GRID HEATER CAN CHAFE AGAINST THE ENGINE AND WEAR THROUGH CAUSING AN ELECTRICAL SHORT IN THE GRID HEATER POWER SUPPLY. THE SHORT CAUSES THE FUSIBLE LINK TO FAIL.
Risk
WHEN THE FUSIBLE LINK FAILS, INSULATION ON THE FUSIBLE LINK CAN IGNITE, CREATING A FIRE RISK IN THE ENGINE COMPARTMENT.
What owners should do
OWNERS WILL BE ADVISED TO REPLACE THE ORIGINAL GRID HEATER POWER SUPPLY HARNESS WITH FUSIBLE LINKS WITH A NEW GRID HEATER POWER SUPPLY HARNESS EQUIPPED WITH FUSES. IN ADDITION, A CLAMP WILL BE ADDED TO SUPPORT THE HARNESS AWAY FROM THE ENGINE COMPONENTS.
Units 2740