How to Wire a Fluorescent Light Fixture Ballast

Shut off the circuit breaker switch that controls the power to the light fixture. If you have a portable fluorescent light fixture, unplug the power cord from the wall outlet.

Remove any light bulbs from the fixture and set them aside. Depending on the design of the light, you may have to pull off or slide out a plastic cover to access the bulb socket. If you have tube-style fluorescent bulbs, rotate the bulb until the pins line up with the opening in the socket and pull the bulb away from the fixture.

Take the casing off the light fixture. You may have to remove a set of screws or release a set of retaining clips with needle-nose pliers before you can lift off the casing.

Snip the four wires running from the light fixture to the ballast with wire cutters if this is a replacement job. Remove the retaining screws holding the old ballast in place. Take out the old ballast and discard it.

Strip the last inch of insulation from the ends of the wires of the new ballast and the light fixture, using wire strippers. Match the two sets of wires by color. Connect each pair of matching wires by twisting the exposed ends together. Slide a wire nut over the ends of the wires and twist the nut to tighten the connection. Use electrical tape or plastic wire caps to insulate the connection points and push the wires into the body of the light fixture.

Replace the light fixture casing and tighten the retaining clips. Insert the light bulbs you removed in Step 2 and restore the power from the circuit breaker or wall outlet.