Abstract: A two motor assembly for driving two fan blades to move air through a heat exchanger comprising a first two speed DC motor comprising magnets for establishing a fixed magnetic field, an armature rotor rotatable to drive a first fan blade, a multiplicity of armature coil turns on the armature rotor, a commutator assembly on the armature rotor, and sets of brushes including a tap brush cooperating with the commutator assembly to alternatively operate the two speed DC motor (1) is a first speed mode wherein (A) a system voltage is applied and distributed across all of the multiplicity of armature coil turns to produce a net total back EMF and armature reaction interacting with the magnetic field to cause the armature rotor to rotate in the first speed mode and (B) a tap voltage intermediate the system voltage reduced across a predetermined number of armature coil turns less than all of the multiplicity of armature coil turns is provided through the tap brush and (2) a different second speed mode.