How to Wire a Ventilation Fan & Light

Turn off the ventilation fan and light unit's circuit breaker. The correct circuit breaker uses a label identifying the room the unit services.

Remove the screw holding the ventilation fan and light unit's electrical box cover with the correct screwdriver, often a 1/4-inch hex-head. The electrical box mounts to the back of the unit's housing. Remove the cover.

Separate the wires in the box. The wires for each of the ventilation unit's appliances use labels for identification: One set reads "Fan," and the other reads "Light." The power to the fan/light unit comes from either a single three-strand wire set with white, black and red insulation or from two separate wire sets containing black and white insulation. The wire set(s) from the switches also contain a bare copper wire.

Remove 1/2 inch from the insulation covering each wire in the ventilation fan and light unit with wire strippers.

Loosen the green-colored ground screw, located on the ventilation fan and light unit's housing, with the appropriate screwdriver, usually a 1/4-inch hex-head screwdriver. Bend the bare copper wire(s) from the switches around the screw. Tighten the screw.

Connect the neutral wires. If a single, three-strand wire feeds electricity to the ventilation fan and light unit, then twist the white wire from the switch to both of the unit's white wires. Both wire sets from the unit contain a white wire. Secure these three wires together with a wire nut. If two two-strand wire sets feed electricity to the unit, then twist the white wire from the unit's "Fan" wire set to one of the switch's white wires and secure these two wires together with a wire nut. Twist the white wire from the "Light" wire set to the second switch's white wire and secure with a wire nut.

Twist the unit's hot wire labeled "Fan" to its switch wire. If a single three-strand wire feeds electricity to the unit, then twist the black wire from the switch to the "Fan" wire set's remaining wire and screw a wire nut over this pair of wires. If two two-strand wire sets feed electricity to the unit, then twist the "Fan" wire set's remaining wire to the black wire from the same wire set that the "Fan" wire set's white wire connects to.

Twist the unit's hot wire labeled "Light" to the remaining switch wire and screw a wire nut over these two wires.

Replace the ventilation fan and light unit's electrical cover. Replace the screw and tighten with the correct screwdriver.