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Give me 5 Minutes and I’ll Fix Your Fluorescent Light

Fluorescent Light Ballast

Two days before Thanksgiving I walked into our laundry to wash my underwear and noticed the light wasn’t working.

After a short three word phrase (use your imagination) I started to have flashbacks about what led to this moment in time.

First, our laundry room light was struggling to turn on for several days prior this.

Then it just stopped working altogether.

Because I like to DIY and my said to get this fixed ASAP I diagnosed the problem as a bad fluorescent light ballast.

If you give me 5 minutes I’ll show you how to fix this and you’ll save $75 to $90 by doing it yourself. Let’s get started!!

Getting Started: How to Check that Your Fluorescent Light Ballast is Broken

You’ll only need three kinds of tools for this project:

  • Combination Stripper
  • Screwdrivers (both Phillips and Flat)
  • Voltage Detector

One clue that your ballast is the reason for a non-working fluorescent light is the light bulbs struggle to turn on.

As I said in the intro, we noticed this happening over a 3-4 week period.

A good way to check that your ballast is the culprit is to turn on a voltage detector and hold it next to the wires supplying power to the ballast.

Test Ballast for Power

If power is going into the ballast and none is flowing to the fluorescent light bulbs this is an indicator the ballast is dead – unfortunately much like the cool old guy named Blue in Old School (for all you Will Ferrell fans, Blue the character dies while, ahem, wrestling!!)

RIP Blue


How to Remove Your Old Ballast and Light

Before doing anything further, turn off circuit that supplies power to the light.

Then double-check that no electricity is running to the light by using your voltage detector. Many thanks to Mark for reminding me that I forgot to add this SUPER IMPORTANT tip.  But that’s why I have great fans like you who catch my absent-mindedness!!!!

There are only a few screws holding the ballast to the fluorescent light.

Remove these screws using a screwdriver but don’t toss them in the garbage. Primarily because you may not get news screws with the new ballast.

You can choose to remove the ballast before or after you remove the fluorescent light from the ceiling.

To avoid having shattered glass all over the floor I highly recommend removing the fluorescent light bulbs. They’re attached to the ballast and you’ll have to detach the plug.

Removing Fluorescent Light Bulb

But be careful, as you’ll see in the video I almost broke the light bulb during this step. I’m such a dummy some times.

Only two screws hold the fluorescent light to the junction box. Use a screwdriver to loosen these screws and just be aware that the light will drop slightly from the ceiling.

Junction Box Screws

Slide the light’s frame and pull it down off the junction box screws.

At this point take a picture of the existing wiring. This will give you a reference and help with wiring the new ballast.

Take a Picture of Wiring

If you’re not particularly strong or have weak shoulders get a friend or relative to help with this part.

Have them hold the light while you unwire the ballast from the junction box. Or, if you really don’t like electricity or your friend/relative (just kidding) you can hold the light instead and let someone else unwire it.

Loosen all the wire nuts. I like to take apart the black or hot wires, then the white or neutral wires, and lastly the ground. It just makes me feel better to do it in this order.

Pull the ballast wires out from the frame.

That’s how simple it is to remove a fluorescent light ballast.


Adding a New Ballast to Your Fluorescent Light

You’ll need to take your old ballast with you to the hardware store. It’s a good idea to call and see if they have the right ballast in stock.

I called around to several places that didn’t have the ballast I needed. And in fact, I still ran into a bit of trouble  with the ballast I bought (I explain at the end of the video).

Place the new ballast on the fluorescent light’s frame and tighten it with the screws that you saved from the old ballast.

New Ballast

Fish the new ballast’s black, white, and green wires through the hole in the light.

Get your friend or relative to hold the light while you wire it to the junction box. Seriously, I had to call my wife into the laundry room to help. I felt bad that she had to hold the light up while I fiddled with the wires.

But, hey that’s what marriage is all about — helping each other through DIY sickness or health!!

If you have kinked wires like in the picture below cut them with your combination strippers and strip off 3/4 of an inch of the insulation.

Trim Kinked Wires


Wire the new ballast in the same fashion as the old one. This time around I recommend wiring the ground first, then neutral (white wire) and lastly the hot wire (black in color).

Twist the wire nut until the connection between the wires from the ceiling and the ballast are secure.

Push all the wires back into the junction box as neatly as possible.

Slide the fluorescent light frame onto the screws you left in the junction box. Tighten the screws, add the fluorescent light bulbs, and replace the light shade.

BAM!!!! You’re done.


Here’s my step-by-step video tutorial for your viewing enjoyment. It’ll show you just how easy it is to replace a ballast, or at least I hope so!!


[tubepress video = “qscaybO-pJo”]


How to Replace a Fluorescent Light Ballast



If you can change out a light switch or outlet you can definitely replace an old ballast that doesn’t work.

As I said in the beginning, you’ll save yourself $75 to $90 doing this fix yourself. Years ago I paid our electrician to do a similar fix at a rental and this is how much the fee was.

Rightfully so, too!! But I like saving money for the grocery list that seems to grow every week.


Got a question or want to add your suggestion to the conversation?

Do so in the comments below. I love hearing from you!!

As always, thanks for reading, watching, and sharing in my DIY adventures.

Have a great day and talk with you soon.

Jeff's Signature No Background





P.S. If you like Facebook check you can follow my over there, too. I love finding great ideas and sharing them with you.

P.P.S. Bathroom lights are just as easy to replace as ballasts. Here’s a nice post on how to update a bathroom light fixture — hope it helps you!



17 comments… add one

  • Mark J December 13, 2013, 2:14 PM

    You didn’t say anything about turning off the power to the ballast and double-checking with your voltage finder BEFORE touching any wires. But hopefully most people know this anyway 😉

    • Jeff Patterson December 13, 2013, 2:17 PM

      Thanks Mark, I should have made that clearer. I’ll add some clarification within the post.

      Yah, it’s not fun getting jolted by electricity. Been there!! The last thing I’d want is for anyone to get hurt.

  • John @ AZ DIY Guy December 14, 2013, 7:44 AM

    Good one Jeff! I like your focus on safety, using the breaker and not the switch. One whack from the secondary side of a ballast will wake you up in a hurry. I still remember hearing a guy screaming, only to realize it was me, when I got lit up by a commercial fixture, years ago. WAY more pain than a poke from a outlet or switch.

    • Jeff Patterson December 14, 2013, 7:47 AM

      Thanks John, getting electrocuted is no fun. I had it happen a just 2 times. Needless to say I don’t like the feeling.

      So even if I have to turn off the main switch in the panel to get electrical work done I’ll do it. Sure the kids get grumpy but for cryin out loud, they don’t need the TV all day long.

      • Brian January 7, 2015, 1:04 AM

        If you were electrocuted, you would not be alive to type this helpful tip.

  • Julie September 3, 2014, 10:41 PM

    Hi Jeff, your tutorial is greatly helpful. Please help me here as I am trying to determine what causes my fluorescent lights not working probably. Our laundry room has one of those four fluorescent tube lights. A few days ago, one of the light kept go off after few minutes. So we bought new light to replace that bad one. However, after replace the new one, those 4 lights would light up brightly but then they went off within a second. I would try to turn back and got the same result. Would that be a bad starter or ballast? Can it be ballast since it’s actually lighted up?

    • Jeff Patterson September 5, 2014, 7:36 PM

      It sounds like a bad ballast to me Julie since the light won’t stay on. So it could be worth it to change out the ballast. Just get an electronic one not a magnetic one, they kinda stink!!!

  • dale brown December 20, 2014, 8:36 PM

    hope the light you or they are changing the ballast in is not sharing a nutral wire with another load thats turned on , like the one in my house. real reason im commenting is ive done the 4 thing ,replace bulbs, ballast, ends and ck power and still have to touch or rub the bulbs to make it work. why? cant find a awnser anywhere and it not just mine , my son and my mom have one too. different houses, location,and purchased at different stores

  • Justin R. January 8, 2015, 8:49 PM

    I have the same fixture you show in the pictures with two round bulbs. When it stopped turning on, I replaced the bulbs. Now, one works and one doesn’t. It’s the wires coming from the ballast, because when I switch them around, the other one works.
    Dumb question, but can I assume I need to replace the ballast?

  • LynneS February 7, 2015, 4:11 PM

    Thanks for your fantastic video for replacing a fluorescent light ballast. I found it on youtube, watched carefully, headed to Home Depot, and got the job done myself. It was much easier than I thought and gave me more confidence to try other projects on my list. Keep up the great work!

    • Jeff Patterson February 10, 2015, 8:10 PM

      Great job Lynne!!!!

      You made my day and I’m so pumped that you’re inspired to do more projects 😀

  • Jack Collins April 13, 2015, 7:58 AM

    Hi…needed to replace an 18″ undercabinet fluorescent. Had to a drill new hole in fixture for incoming wires so I could place it at the same spot as old fixture. This necessitated having to move ballast. Would the moving of the ballast in the new fixture cause a safety problem?

  • Sid June 13, 2015, 10:44 AM

    I need help. i have a kitchen fixture that has 4 T8 bulbs. I have replaced the ballast a few years ago. None of the bulbs worked the other day when I flipped the switch. I removed a bulb and put it in my garage fixture and it worked. So I replaced the ballast again. I have juice going to a 4 sockets, but the light do not come on. Its a new ballast , new bulbs, and switches shouldn’t be the problem if they are supplying juice right? What else can it be? Thanks for any advice

    • jeff October 26, 2015, 12:04 AM


      Did u figure out the cause yet?

      I’m having the same problem!

  • osu13 July 22, 2015, 8:56 AM

    Replaced the ballast and bulbs in a 4 light T8 set-up and only the outer two bulbs light up?

  • Larry October 21, 2015, 4:11 PM

    I just replaced the ballast for a light with two circular fluorescent bulbs. The old ballast had a ground wire. The new one doesn’t and only the inner bulb turns on now. Did I just get a bad ballast?

  • HG November 9, 2015, 9:31 AM

    I have questions and statements…
    Our bathroom has four foot size fluorescent lamps over a large mirror. I replaced all four with Home Depot matched bulbs. Three had worked before this exchange but colors weren’t identical.
    When I installed the lamps (while hot) some didn’t want to light up until I found a particular rotating location. All four had now lighted up. I turned them off for a few minutes to confirm all is well. They all started up again.
    The next day only one started up and that is now working consistently. The others are consistently dead.
    All lamps are using their own ballasts.
    Could there be a contact cleaner issue on the socket ends? The bulb’s pins are obviously new. Why would these work one day and then fail the next?
    This brings me to another issue. The cost of new ballasts vs substituting LED 4 ft bulbs in the same fixture (minus the ballasts).
    Are the LED bulbs as bright and at a COOL WHITE color of about 3000K temperature, anything higher and it would be unpleasantly going towards daylight.
    Now my statements….
    In our small laundry room we had a double Circline fluorescent fixture which worked okay, yet it needed periodic bulb replacement.
    Such bulbs aren’t cheap either and no fluorescent fixture appreciates constant ON-OFF usage.
    So I removed the complete fixture and replaced it with an inexpensive plain screw in porcelain type which holds a CFL of about 20 Watts. The bulb is completely exposed which don’t bother us the least because it’s a laundry room and on the ceiling. This has failed once in two years of usage. So in seconds I unscrewed it and replaced it with a new one.
    I also understand that regular fluorescent lamps don’t like high humidity which is to be expected in bathrooms, laundry rooms and obviously in FL. Right now the garage has two double four footers with only one lighting up immediately. On a humid day the second one can take hours before lights up unless I flick the switch a few times which is bad for the working one. The garage has a ten foot ceiling so Im considering doing the same thing as the laundry room…and as LED’s are coming down in cost these may be used too down the road.

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