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Why Fluorescent Lamps May Not Be Bright

My kitchen fluorescent lights have dimmed down to the point where we can barely see that there’s electricity even getting to them…

Understanding Fluorescent Light Fixtures

Question: My kitchen lights have dimmed down to the point where we can barely see that there’s electricity even getting to them. The bulbs are fluorescent. At first, only one bulb dimmed out, then a day or so later the other went. They are both operated by the same switch.

We tried other bulbs, but they are all dim in those sockets. There are no new power loads in the house to blame for the dimming. They just stay dim all the time. No other circuits in the house are doing this.

Thanks in advance,

This electrical question came from: Dave, a Homeowner from Waterford, Maine.
See more about Home Wiring for Maine

Dave’s Reply:
Thanks for your electrical question Dave.

Dim Fluorescent Light Bulbs and Bad Lighting Ballast

Dave, fluorescent light bulbs that are allowed to burn out in the socket can actually cause the ballast to burn out and need replacing. If fluorescent lamps start to burn out or flicker, then it is time to replace them, and always replace both lamps as a pair for a longer lasting ballast.

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4 Responses to “Why Fluorescent Lamps May Not Be Bright”
  1. Dave Rongey says:

    Hi Avery,
    Installing the original lamps with new ballasts for a short time should not have caused the ballasts to be ruined. Double check all of the wiring connections to make sure they are correct and the lamps are properly installed.
    I hope this helps to get your light fixture working,

  2. Avery says:

    None of the 4 fluorescent bulbs were working in my light fixture so I replaced both ballasts, and put the same bulbs back in. When I turned on the fixture the lamps glowed dim. Did I ruin the ballast by putting the same bulbs back in for less than five minutes? I put four new bulbs in the fixture but they are still dim.

  3. Dave Rongey says:

    Hi Mike,
    From what you have described, each 2 light fixture has 1 ballast. With fluorescent lights, if the lamps are allowed to burn out in the socket then there is a great chance that the ballast will need to be replaced along with the lamps. For more about repairing fluorescent light fixtures see this article: http://ask-the-electrician.com/fluorescent-lighting-problems-and-how-to-fix-them/
    I hope this helps,

  4. Mike Heffernan says:

    My kitchen fluorescent light has 8 F40 T12’s in them. I replaced all the bulbs. When I turned them on 4 were working right and 4 are just dim and stay dim. No flickering. There are 2 sides with 4 bulbs on each side that have 4 different fixtures. Each fixture has 2 bulbs. Does each separate fixture have a ballast, or are there 2 ballast for all 4?

    Confused in Spring,Texas Mike.
    Thank you in advance.