A
system for supplying supplemental heat to a vehicle, particularly a vehicle with a
diesel engine, A driven viscous plate with different viscous
clutch faces on either side is provided between the engine and the
coolant pump. One side clutches to the engine structure (ground) to generate heat, and the other side clutches to the
coolant pump to vary the pump drive. The two sides are controlled by a valve operated by signals from the engine computer. The valve varies the supply of viscous fluid from a common reservoir independently to both sides of the driven viscous plate. The
signal from the
engine control unit is based on the instantaneous desired supplemental heat and
coolant flow. In another embodiment, two separate viscous clutches are utilized and positioned on opposite sides of the
coolant pump.