Need help quick on 3 way light switch


  #1  
Old 05-22-20, 02:43 PM
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Need help quick on 3 way light switch

Asking for quick help because I am only in town at this house for about 24 hrs.

Issue is this:

Foyer lights, (2 recessed in ceiling) with 2 3way switches. Call it switch #1 and #2

if sw1 is down then sw2 works fine.
if sw1 is up then sw2 doesn't do anything.

My initial suspicion is that one of the switches is wired wrong. But that is why I am turning to you.

The single wire that has constant voltage on it, is connected to different places on the 2 switches. Should the constant hot wire be in the same place on both switches?

Anything that you think I should check before just replacing the switches to see if it is a bad switch?

I don't have my digital meter with me unfortunately, I only have on/off tester with me and that is what I am using for now.

Thanks for any help. Very much appreciated.
 
  #2  
Old 05-22-20, 03:06 PM
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additional info is this:

if sw2 is up, I have no voltage on any terminal on sw1
if sw2 is down, I have voltage on one of the traveler terminals on sw1
 
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Old 05-22-20, 03:44 PM
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There is only one hot wire. It will be found on the C terminal at one end only.
The wire that is hot will be hot regardless of any switch position.

Once you determine which wire is always live/hot. The other two are travelers.
The traveler colors will usually be the same at both ends. You can also look into the box..... follow the traveler wires.... they should go into one cable only.
 
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Old 05-22-20, 04:44 PM
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Sounds like the problem is at sw2.
Pull the switch out without disconnecting any wires. Tell us about all the wires in the box(omit grounds).
Or take a picture and post it. Turn power off first of course.
Look at the colour of the screws. One will be black. Top, right, left means nothing. Ground will be green.
 
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Old 05-22-20, 05:56 PM
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That's what my first guess is. sw2. I already have the switch pulled out but not disconnected yet. Looks like the wires that should be connected to the top terminals which I believe should be the travellers are coming out of the same piece of romex. One which is red and one black. Then there is another black wire from a different piece of romex that is connected to the common. I am assuming that it goes to the light. I know what happens when you assume though. I am going to try and attach pics if I can.

 
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Old 05-22-20, 06:04 PM
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Here is a pic of the sw and the box

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Old 05-22-20, 06:19 PM
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The black and red from the same cable need to be on the gold screws. The black from the other cable needs to be on the black screw. I can not tell from the photos if this is how it is currently connected.

Use the screw terminals not the back stabs. Back stabs are a very common source of poor connections.
 
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Old 05-22-20, 06:24 PM
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Went with your suggestion that it was sw2. Replaced sw and working fine now. Thanks for the help.
 
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Old 05-22-20, 06:27 PM
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That looks like a 4 way switch.
Are there 4 screw terminals..... excluding the ground screw... on it ?
 
  #10  
Old 05-22-20, 06:46 PM
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No just 3 terminals plus a ground. And I did definitely use the screw terminals and not the push-ins. I don't like those either. Don't trust them. Thanks, again

Did industrial maintenance troubleshooting in a tire factory for 30yrs. Primary mechanical / secondary electrical. But most of our electrical was 3 phase 460v. So I do some residential wiring and but my confidence isn't that much sometimes. And sometimes it just helps to get someone elses opinion. I have never been one to think I know it all and I won't hesitate to ask if I'm not sure.
 
 

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