Replacing a Light Switch

Old 01-06-14, 06:22 PM
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Replacing a Light Switch

I need help wiring a switch.

I have a light switch in the foyer which I'd like to replace with a Decora light switch. The existing switch is tied in with 2 other switches, one downstairs and one upstairs. You can flip any of the 3 switches and the foyer lights will go on or off.

There are 4 terminals + ground on the existing switch:
  • The top 2 terminals have a red wire going to the left terminal, and a red wire going to the right terminal.
  • The bottom 2 terminals have a black wire going to the left terminal, and a black wire going to the right terminal.
  • The underside terminal (ground) has a bare copper wire going to a wirenut tying it to the ground wires coming from both romex ends.
  • The white wires coming from the romex are wire-tied together.

I want to replace the switch with this new Decora switch, but the Decora only has 3 terminals + ground. How do I wire this?
Old 01-06-14, 06:28 PM
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You have a 3 way switch. You need a 4 way switch. Pay attention to the cable pairs and how they are shown on the wiring diagram for the new switch.

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