99A9861 | Genuine Horton® Fan Clutch DM Advantage, SE24 Cummins, 12

• Improves fuel economy
  • The engine doesn't have to constantly drive a large cooling fan.
  • This is especially important on heavy-duty trucks where the fan can consume significant horsepower.
• Reduces engine load
  • Less energy is used to spin the fan when extra cooling isn't needed.
  • More engine power is available for moving the vehicle.
• Maintains proper engine temperature
  • The fan engages when coolant temperatures rise.
  • Helps prevent overheating during heavy loads, hot weather, or slow-speed operation.
• Reduces noise
  • Large engine fans can be very loud.
  • A disengaged fan clutch keeps fan speed lower, reducing noise.
• Speeds engine warm-up
  • By limiting airflow through the radiator when the engine is cold, the engine reaches operating temperature faster.
  • This can improve efficiency and reduce emissions.

Signs the fan clutch is stuck engaged

• Very loud fan noise ("roaring" sound), especially during acceleration.
• Reduced fuel economy because the fan is constantly drawing power.
• Loss of engine power or sluggish acceleration.
• Fan seems to run at high speed even when the engine is cold.

Signs the fan clutch fails to engage

• Engine overheating, especially:
  • In traffic or at low speeds
  • While towing or hauling heavy loads
  • Climbing hills
• Temperature drops when driving at highway speeds because natural airflow through the radiator helps compensate.
• Air conditioning performance may worsen at idle because less air is moving through the condenser.