Dimmer Switch - 3 Wires


Old 04-01-18, 06:06 AM
Thread Starter
Join Date: Apr 2018
Posts: 1
Received 0 Votes on 0 Posts
Dimmer Switch - 3 Wires

Can someone help me figure out how to replace my standard single switch with a dimmer switch? From what I can tell, the current setup has an extra wire (note 3 black and 3 white, instead of what I expected which was 2 black and 2 white). I believe there is only 1 switch for the 1 light and no associated outlet in the room, so what is the extra wire for? I tested the fuses and the closest electrical outlet is on a different fuse than the light, so where is the third wire passing through to? Do I simply need to attach the third wire to the red dimmer wire marked as (3-way), even though its not?
Sponsored Links
Old 04-01-18, 06:48 AM
Geochurchi's Avatar
Join Date: Nov 2012
Location: United States
Posts: 4,750
Received 67 Votes on 63 Posts
Hi, simply remove the old switch which should have 2 conductors on it and install the dimmer to those 2 wires.
Old 04-01-18, 08:21 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 58,576
Received 1,042 Votes on 966 Posts
Welcome to the forums.

Your three white wires should be combined and wire nutted.
Your switch most likely has screw terminals and push-in connection. Someone used the lazy man connection and used both the screw terminal and push-in at the same time.

The black circle shows two wires. One on the screw and one pushed in. They are connected inside the switch. These would be a hot wire to the switch and one to something else along the line. The red circle is a wire by itself. This would be the load wire to the light.

You'd connect the two blacks together and go to one of the dimmer wires.
The single wire is the other connection.

Name:  switch.jpg
Views: 92
Size:  35.8 KB
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: