Electrical – Why does the switch trip the breaker after light fixture replacement

electrical

I'm trying to replace a ceiling light in the kitchen. The light is controlled by a wall switch. I took the light off and I have 2 black and 2 white wires in the box. I shut the switch off and the box was still hot.

I found the breaker that controls the hot wire in the ceiling box. I put the black wires together and then the white wires together and then attached the black from the new light with the black wires and the same with the white. I turned on the circuit breaker with the switch off and the light came on. I turned the wall switch to the on position and the light went off and blew the breaker.

Do I have to put all three whites together with wire nut and then one black to black light lead and other black to white lead from light? confused

Best Answer

You have a typical switch loop, like so (green is bare ground, which you may not have):

enter image description here
(source: do-it-yourself-help.com)

However, your white and black to the switch may be reversed. Really, it doesn't matter, though. Connect the white from the source and one of the switch legs to the fixture. Connect black from the source and the other switch leg.

To clarify, you want power running through the switch, then through the light, with no other possible path.

When you connected things the way you did, you set it up so that flipping the switch resulted in a direct short. That's bad, obviously. I suggest brushing up on basic electrical theory before tackling any more wiring projects.