Connect a light and a fan to a new switch. Wiring a combination bathroom ceiling exhaust fan and light unit with the fan and light being controlled by separate wall switches is an easy project even for a beginner. Wiring Diagram Bathroom Bathroom light fittings, Ceiling The electrical wiring for separate switching of the bathroom exhaust fan and the light fixture will require identifying the existing circuit and existing switch wiring. Bathroom fan light wiring diagram . 3 way fan switch wiring diagram. Combination light, fan and heating units can be incredibly helpful in smaller bathrooms and similar areas in your home not served by heating vents. Connect the black (fan) wire to the black wire in the /3 cable. To wire a 3 way switch circuit that controls both the fan and the light use this diagram. Rewiring your bathroom circuit to allow fan and light to be operated independently. Bath vent fan wiring connections. Wiring bathroom fan and light on one switch diagr...