I need to install a dimmer switch in my sons room. I bought one a single pole slide dimmer that has 2 black wires and one green. Now I understand the instructions given(One black is hot the other is neutral and the green is ground) however when I went to remove the old switch my confusion began. My current working switch has 2 wire coming into it. Of those wires one has a black and white wire and the other has a black, white and red wire. The two white wires are connected together and both black wires are connected in the same terminal on the switch. The red is connected to the other terminal on the switch... Which wire(s) are connected to the new switch?

Thanks in advance

Well, I don't know for certain what you have, but the code says that black wires are hot, red wires are hot but switched, white wires are neutral, and green or bare wires are the safety ground. However, for safety reasons never assume that the guy ahead of you knew what he was doing.

D1-TIC

I need to install a dimmer switch in my sons room. I bought one a single pole slide dimmer that has 2 black wires and one green. Now I understand the instructions given(One black is hot the other is neutral and the green is ground) however when I went to remove the old switch my confusion began. My current working switch has 2 wire coming into it. Of those wires one has a black and white wire and the other has a black, white and red wire. The two white wires are connected together and both black wires are connected in the same terminal on the switch. The red is connected to the other terminal on the switch....Which wire(s) are connected to the new switch?

Thanks in advance
Just concentrate on the switch you want to replace. Keep these wires connected to each other as they are now, just replace one switch contact with one of the two black wires from the dimmer, and the other wires from the switch with the other black dimmer wire.
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If there is no earth, just keep that not-connected, though it would be better to draw a real earth wire into the pipe from the nearest earth point.
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The multiple wiring is just interconnecting other switches or powerpoints elsewhere. They should remain wired as they are now.
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;)

So I connect both of the current black wires to one of the black wires from the dimmer(hot). The red wire would get connected to the other black(neutral) and then I connect the ground leaving the white wires connected together as per current?

Does your existing switch have three terminals or two. Don't count the green ones which are ground.

Can the existing switch be turned on from two locations?

Your newly purchased dimmer has 2 + a ground.

The light in the room can only be turned on from this switch. What is confusing me is the red wire and the two white wires that are connected together.

Wiring a switch should be simple -- do not try to rewire it according to wire color

One or more wires are connected to one screw -- transfer them to a (gold) screw on the new switch

The secound screw has one or more wires -- just transfer them to a (gold) screw on the new switch

If there was a bare or green wire on frame of switch -- transfer it to the new switch -- (green) screw

Two blacks on one switch terminal -- red wire on the other switch terminal -- do not touch whites

both black wires are connected in the same terminal on the switch.


Connect these two wires and one of the black wires from the switch with a wire nut. Connect the red wire to the other black wire from the switch with a wire nut.