How to Change the Ballast in a Fluorescent Light Lamp Holder

The ballast is the part of a fluorescent light fixture that creates a high voltage surge to cause the gases in the tube to glow. It's sometimes called a starter. Frequently, the first clue that a ballast has failed is a strong burning odor. Changing the ballast is a straightforward process for anyone with confidence working with wiring. When you change the ballast in a fluorescent light holder make sure you replace it with exactly the same kind.

Difficulty: Moderate

Instructions

Things You'll Need:

• Wire nuts Nut driver

1. Turn off the power to the fixture.

2. 
    

   Remove the light fixture cover and then the light bulbs or lamps. Remove the bulbs by gently rotating them until the small metal prongs at the ends of the bulbs line up with the slots in the bulb holder. Slide the bulb out.

3. Open the ballast cover. This is usually done by turning the metal tabs at the center of the fixture.

4. 
    

   Find the wire nuts that connect the wires coming out of the ballast to the wires that go into the fixture. Separate the wires at the wire nuts. If there are no wire nuts, cut the wires about a foot from the center of the fixture on both sides.

5. 
    

   Remove the ballast by unscrewing the nut that holds it into place.

6. Take the ballast to the hardware store, and replace it with the same model. You may also need to know the number of bulbs in your fixture, their wattage and length.

7. Install the new ballast by screwing the nut back into place. Make sure that the wires at each end face the like-colored wires in the fixture.

8. Attach the red wire on the ballast to the red wire in the fixture. Do this with the blue, black and white wires. Strip 1/2-inch of insulation from each wire end and attach them with wire nuts.

9. 
    

   Put the ballast cover back on. Put the fluorescent bulbs back in. Test your light.

Tips & Warnings

• Allow the light a minute or two to start the first time. There may be two ballasts in a fixture with four bulbs. Replace both at the same time.
• Fluorescent bulbs are fragile.

Resources

• Fluorescent Bulb FAQ
• Troubleshooting Fluorescent Bulbs
• In-Depth Information on Fluorescent Fixtures