Trying to retrofit LED can lights by bypassing the ballast. First light I retrofitted had 1 white, 1 black, and one green ground wire in the junction box, along with 2 red and 2 blue leading to the fixture. wired 1 blue and 1 red to the black and white and the light worked perfectly!!!

Next light however, was a problem. the 2 lines coming into the junction box had 2 lines coming out of each; both black AND white. The black from one line was connected to the white of the other and vise versa.

At first I connected both whites together and both blacks, but when I turned the breaker back on it immediately tripped.

Then I connected 1 black and one white from each similar to how it looked before I started messing with it and the breaker still tripped. So I separated all lines and capped them off so I could use the rest of the lights in the kitchen and the breaker works fine. I have no idea what to do, and I don't really know anything about electrical work.

Any ideas?

  • 4
    "I don't really know anything about electrical work." I strongly suggest getting a book at your local library, and learning. A book will tend to be better organized than surfing the web, and more likely to apply to the specifics of your local area/country/etc. Otherwise, DIY is not the best path when you "don't know anything" and getting it wrong can burn your house down or otherwise kill you. Ignorance can be cured, but you need to cure it before you dive into some things, or the consequences can be dire, and a lot more expensive than hiring someone who already knows.
    – Ecnerwal
    Commented Jun 18, 2019 at 15:16
  • You may have a switch leg in splice show the electrician all the stuff you touched and if you do not have a meter .stay away from electric work.
    – user101687
    Commented Jun 18, 2019 at 18:37

1 Answer 1


Oh, why on earth did you do that?

Wires are not color coded for the benefit of novice installers. They are color coded because cables only come one way: with black and white wires. Those wires serve a wide variety of functions, but they are always black and white because cables are; they are not color coded by function unless you do this yourself with colored tape. (Which I in fact do).

You took apart wires you did not need to take apart. You saw a black wire from the ceiling connected to only a white wire from the ceiling: it was not connected to the ballast in any way whatsoever, yet you felt you just had to dismantle it anyway.

I call this "trying to learn electrical by dismantling your house". Seems pretty silly when I put it that way, but it made sense at the time, I'm sure.

Another thing that often bites novices is the sense that the guy who did this work previously is an idiot. Maybe, but you certainly are in no position to judge.

Unfortunately, reversing this mistake is hard. It may be time to call an electrician in.

If you really, really want to press forward, then identify the two cables in this box. Select one cable and identify the white and black from that one cable. Connect the lamp's hot and neutral to those two wires alone, leaving the others capped off. If that doesn't bring it to life, try the other cable.

In the future

Pay close attention to how things were wired before, and only touch the things you actually have to.

In this particular case, you should be unhooking all the wires coming out of the ballast, and coiling then up and wrapping them with tape to get them out of the way, so they are out of sight and out of mind. I don't like cutting wires on functioning ballasts. At that point, when you exclude those wires, there should 2 places that the black and white from the ballast went to. Those are the only 2 places you are concerned with, keep your schnozz out of everything else.

Oh, and know the other thing that will save you an electrician call. When replacing receptacles, check to see if the tabs are broken off.

  • 3
    Whether it is electrical or anything else around the house it just doesn't make sense to take something apart without taking a picture of it beforehand. This was actually a task 20 years ago. Now with cell phones you are a bit of a dufus if you don't do it. Even with good electrical experience, if you don't take a picture you are assuming someone would have wired something how you would have or used your best practices.
    – DMoore
    Commented Jun 18, 2019 at 18:18
  • 2
    @DMoore true enough, but if people did that, there wouldn't be any need for this forum :) The trouble with these bare novices is they really think what's in that box is designed to make their job easy, and they forget they are in a professional trade's world. Commented Jun 18, 2019 at 18:47

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