Hot Topics: One Switch with Three Black Wires

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Original Post: Need Help! Single Pole Switch with 3 Black Wires

cbailey22 - Member

Need Help! Single Pole Switch with 3 Black Wires

Hi all,

I am replacing my single pole light switch and noticed when I removed the old switch that there are three black wires coming from the box. All the white wires are capped together and the same is for the ground wires. Of the three black wires, only one of them is hot. The old switch was attached with two blacks inserted into the back of the switch with another black attached to the screw. I am confused on how to rewire the switch. I forgot to write down which wire went where when I removed the old switch so it is my own fault. Any help would be greatly appreciated.

Thanks.

Nashkat1 - Member

Welcome to the forums!

"The old switch was attached with two blacks inserted into the back of the switch with another black attached to the screw. I am confused on how to rewire the switch."

One of the two non-hot black wires is the light feed and the other is a feed to other loads - possibly some receptacles, but it doesn't matter.

With the power off, connect the black hot wire to the old switch. Connect either of the other two black wires to the other screw on the switch. Turn the power back on and turn the switch on. The light will either turn on or it won't.

If the light turns on, the second black wire you connected to the switch is the switch feed and the unconnected black wire is the feed to the other loads. If the light doesn't turn on, then it's the other way around: the connected wire feeds the other loads and the disconnected wire is the light feed.

Turn the power off and mark the wires before you disconnect them. Terminate the light feed to one of the two screws on the new switch. Do not use backstabs, even if the new switch has them. Splice the hot wire, the feed for the other loads and a short black pigtail together. Trim and cap the splice. Connect the pigtail to the other screw on the new switch.

cbailey22 - Thread Starter

Thanks Nashkat1, that worked.

Nashkat1 - Member

Glad you got it solved, and thank you for the feedback.