A fan drive assembly for a vehicle, which can provide reverse fan flow. The assembly has a fan, where separate forward and reverse clutches are coupled to the fan. The reverse clutch has a greater torque capacity than the forward clutch, such that when the reverse clutch is applied, the forward clutch is made to slip, allowing for the reverse rotation and flow of the fan.

A system for controlling a fan of a vehicle engine. The system comprises: i) a fan configured to selectively cool the vehicle engine; and ii) an engine control module configured to: a) turn on the fan when the engine temperature exceeds a selected temperature threshold; b) determine when the vehicle engine is operating in an engine braking mode; and c) in response to the engine operating in the engine braking mode, turn on the fan when the engine temperature is below the selected temperature threshold. The engine control module turns the fan off as a means of hardware protection of the fan clutch even during engine braking modes.

A system for controlling a fan of a vehicle engine. The system comprises: i) a fan configured to selectively cool the vehicle engine; and ii) an engine control module configured to: a) turn on the fan when the engine temperature exceeds a selected temperature threshold; b) determine when the vehicle engine is operating in an engine braking mode; and c) in response to the engine operating in the engine braking mode, turn on the fan when the engine temperature is below the selected temperature threshold. The engine control module turns the fan off as a means of hardware protection of the fan clutch even during engine braking modes.

A fan drive for a working vehicle includes a speed shift unit and a fan in series to the speed shift unit. The speed shift unit includes a clutch unit and is configured to discretely provide a first non-zero speed ratio and a second non-zero speed ratio. The clutch unit is configured to alternatively connect the first or the second non-zero speed ratio to the fan.