(I am a new homeowner.)

I went to replace a some fluorescent tubes that looked like they burned out, but after disassembling it a little to get the tubes out, I saw something a little alarming:

There was a black sticky substance on the inside cover of the housing:

There was a black sticky substance on the inside cover of the housing

Picture #1 of what looks like a "burned" wire and "melted" electrical tape

Picture #1 of what looks like a "burned" wire and melted electrical tape

Picture #2 of the same

Picture #2 of the same

Closeup of the "melted" electrical tape:

Closeup of the melted electrical tape

So, my questions are:

  • What happened here?
  • Were things about to catch fire?
  • Now that the fluorescent tubes are out is it safe, since the circuit is not complete?
  • Is this something I can fix, keeping in mind that I have no experience with anything electrical? If so, how do I fix it?


The electrical tape was not melted, and the wire was not burned. The culprit was indeed the ballast. Here are the leaks:

The ballast

Thanks, lqlarry!

  • 1
    great pics. lqlarry is spot on. replace the fixture Commented May 3, 2012 at 12:50
  • 1
    Nice picture of the date code: Sep1965...that means the warranty ran out in 1970. I think that ballast got its moneys worth.
    – lqlarry
    Commented Jul 28, 2012 at 1:25

3 Answers 3

  1. You didn't show the ballast, (the black boxy thing with all the wires coming out of it in the fixture) so my guess is that it went bad and some of the potting insulation around the coils of the ballast over heated and melted. (Since I cannot see the whole fixture I'm just guessing about that.) It looks like the black on the cover is a tar type residue but I really would not touch it. It is sticky and a mess to get off.
  2. I doubt anything was catching fire, but when it happened there would have be smoke and a really stinky smell. If you smell the ballast you will see what I mean. But back to the fire, I'm sure this has caused fires in a very few cases.
  3. I would disconnect the power or turn the switch off. The ballast has a thermal cut-off that would probably de-energize the ballast, but it still has power.
  4. It can be fixed, but for a DIY'er it is easier to change the whole fixture. To fix it you would have to wire in a new ballast and that would be 8 wires, where a new fixture would be only 3, a hot, neutral and ground.

If you do it yourself, make sure you turn the breaker off before taking the old fixture out. Out of the ceiling will be either a black or red, a white and a green ground. A new fixture would show you exactly where to put the wires. If you have a friend that knows how to do this then get your friend to show you how so you can see what it takes.

  • I would also advise a DIYer to replace that fixture. Sure looks like the ballast leaked. Commented May 3, 2012 at 12:49
  • Thanks, lqlarry! It didn't even occur to me that there was way too much tar stuff to come from a bit of electrical tape. When I get back from work tonight, I'll take a closer look at the ballast. You rock!
    – anon
    Commented May 3, 2012 at 13:54
  • 3
    That black "Tar" you see from the ballast is PCB, which is a cancer causing substance. It is no longer allowed to be used in ballasts. If you have other fixtures of this type in your house, you should also change them. Most of the newer ballasts are electronic and will be labeled Non PCB.
    – SteveR
    Commented May 3, 2012 at 18:39
  • 1
    @SteveR - shhh! ...Do you hear those noises? Those are the sounds of money being sucked out of my wallet and upcoming weekend hours being consumed by finding and replacing these ballasts...
    – anon
    Commented May 3, 2012 at 21:46
  • 2
    @anon-Unfortunately it is a serious health issue, especially when the ballast faults and you smell that horrible odor, it means you are breathing that in. And they inevitably do fail, its' just a mater of time:)
    – SteveR
    Commented May 4, 2012 at 12:29

The ballast failed because of arcing caused by an incorrect connection. IE your elecrical tape connection was loose and over time the small contact points increased in resistance. This could have been prevented by following code and installing a wire nut instead of twisting the wires together and taping them.


There's nothing wrong with the fixture. I retrofit fixtures like this all the time. In fact, a good, stout old fluorescent fixture is better than any of the new replacements made out of flimsy sheetmetal.

However, the Ballast has failed. And this is time for an upgrade anyway. This is an old "magnetic" ballast, which works with specialized transformers. To keep the transformers from buzzing, they fill the ballast with tar. The aging transformers run hotter, melting the tar until it leaks out.

There's nothing wrong with the wires, they were just dipped in tar. You can clean it off the wires with paint thinner and patience if you really want to.

Other than that, you can disregard the tar.

The "electrical tape splice" is terrible workmanship and you will be replacing it with a proper splice - a blue or orange wire-nut should suffice.

Decide what kind of fluorescent tube you want to use going forward:

  • What you have now, fluorescent T12, is obsolete and tubes may become scarce. Color quality is absolutely superb, as high as 98 CRI, because the gov't outlawed all low-color-quality tubes in an attempt to run T12 off the market.
  • Fluorescent T8 is the latest of fluorescents and performs well and CRI is also top notch (90-98). I recommend rapid-start or programmed-start ballasts as the wiring will match. Instant-starts will be confusing to wire.
  • Direct-wire LED is the up-and-comer, but CRI isn't quite as good (typically 70-80 unless you are a very finicky buyer).
  • Do not use plug-and-play LED. Those require ballasts and yours is dead.

Historic fluorescent tubes have a CRI around 35.

Once you decide on the tubes you want, pick the ballast you need (none for direct-wire LED, T8 ballast for T8 tubes, T12 ballast for T12 tubes). Don't be surprised when the new ballast is a feather compared to the old one.

Turn off the circuit, cut the wires right at the chassis of the old ballast, remove the old ballast and fit the new one. We describe wiring diagrams in other questions on this site. Then fit the new tubes that match the ballast, and enjoy the new light!

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