three way switch problem


Old 10-03-05, 05:40 AM
Visiting Guest
Posts: n/a
Question three way switch problem

I'm troubleshooting two three way switch hooked to five "can" porch lights. One switch is at the front door with the other at the back door. The back door switch has unfamiliar wiring with two cables - three wires in each of black/white/red. These were wired as follows:

c#1 black wired with nut to c#2 black
c#2 red wired to switches travel (brass) connector on ground side.
c#3 white wired to either common or brass on common side (didn't write this down)

c#2 black wired with nut to c#1 black
c#2 red wired to switches travel (brass) connector on ground side (with c#1 red)
c#3 white wired to either common or brass on common side (didn't write this down)

I pulled off all wires, restored power, and put volt meter on them. I found 120ac on two (2) wires. Both c#2 (red) and c#3 (white) show 120ac on them .. I retested several times to be sure.

I can't find this configuration anywhere I've looked. I'm familiar with connecting the hot wire to the 'common' but in this case that would cause a short when switched to the other hot wire.

It seems the two hot wires would have to go on the travel connections with the remaining hooked to the common .. but would apprecaiate verification and input on this.

Any thoughts on why it's wired this way (i.e. switch-fixture-switch or switch-switch-fixture or etc) would be greatly appreciated along with 'how' this should be wired.

Oh - the front door switch has one cable with black (common) being the return and red/white hooked to travel connectors. It was easy .. black tested zero resistence with other two testing infinite resistence.
Sponsored Links
Old 10-03-05, 06:00 AM
Join Date: Sep 2003
Location: Central New York State
Posts: 13,973
Received 0 Votes on 0 Posts
You're right, this is unusual. However, I think you are wrong about the voltages.

I can offer no explanation for the use of 14-3 (or 12-3) where 14-2 (or 12-2) would work. I think you have a switch loop and that the extra red wire doesn't need to be attached anywhere.

I think that you properly measured 120 volts on the white C3 wire, but that the 120 on the red c2 wire is not really there.

I suggest that you open up the recessed lights and investigate the wiring there. It will probably help us all to understand what the wiring is there. Please let us know what you find.
Old 10-03-05, 09:36 AM
Join Date: Feb 2002
Location: port chester n y
Posts: 2,117
Received 0 Votes on 0 Posts
"terminals", not "connectors"--- is this a 3-terminal switch or a 4-terminal switch??

"brass connector on Ground side" (of a switch?) ---- all device Grounding terminals are Green
Old 10-03-05, 03:51 PM
Visiting Guest
Posts: n/a
response to racraft

re: racraft response: thanks for your helpful reply. I was very surprised to see voltage on the c#1 red but I was careful and checked it a couple times (black meter lead on bare ground wire and red lead on c#1 red wire). It was same each time - showing exactly the same voltage as c#1 white. If not for that I wouldn't have needed a post. I rechecked my first post - it is accurate.

As per you advice I'll check the the 'can' light wiring. There are multiple porch lights serviced by these two switchs - I'll check the first and last and post the results. Again thanks for your helpful suggestions.

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: