An apparatus and method are provided for facilitating the cooling of engine coolant flowing through a radiator operatively connected to the engine of an engine-driven, electrical generator set. The engine has a crankshaft rotatable about a first axis and a radiator having a first side directed towards the engine and a second side. The apparatus includes a fan positionable on the second side of the radiator that is rotatable about a second axis generally parallel to and vertically spaced from the first axis. The apparatus includes a thermally responsive clutch having a driven portion. The clutch is movable between a first disengaged position wherein the driven portion is isolated from the crankshaft and a second engaged position wherein the driven portion rotates in unison with the crankshaft in response to a predetermined temperature. A fan drive system interconnects the driven portion of the clutch and the fan for translating rotation of the driven portion to the fan.