A viscous fluid clutch includes a rotor attached to an output from an engine, a stator attached to a fan assembly and a coil assembly having at least a portion attached to the stator. A first gap is defined between the rotor and the stator and a second gap is defined between the rotor and the coil assembly. The first and second gaps are filled with a magneto rheological (MR) fluid. The coil assembly creates a magnetic field in the first and second gaps to vary the viscosity of the MR fluid to produce a variable speed viscous fluid clutch. The coil assembly includes coil windings which are supplied with power through a slip ring assembly. Both the coil windings and the wiring between the slip ring assembly and the coil windings are isolated from the magneto rheological fluid.