3 way switch question

[bjochman]

Having a problem with a 3 way switch, one switch will turn the lights on the other will not. Doesn't matter the position of the non-working switch. The switch that does turn lights on has three wires, black-red-white. The black has 120V on it when testing with multimeter. The other switch also has three wires, black-red-white (with black tape on it). With power off and wires disconnected I'm not getting continuity on any of these wires. The one light I can get at only has two wires, the second light it controls is a can and I can't get at the wires. Any ideas on what to try?

 

[Milton Shaw]

I have found some 3 way switches actually are wired differently on the wire locations on the switches. Some the common is on one end and the two runner wires to go to the other switch are on the other end. I have seen some that are that way on the side, both runners on one side of the switch. If you have different brand switches you may have this problem. Check your switches and your wiring. The black hot should go to the common terrminal the red and white(w/black tape) to the runners on both switches and the common on the other switch should go to the light. You don't mention any other wires so you might not be feeding the switch from one of those boxes you may be feeding the power from the middle which complicates things. Get a wiring diagram off a new switch and see what I am talking about.

 

[Dusty Floor]

Three-way switches have 3 terminals. One is common, and the other two are travelers.

Wired correctly, a hot wire connects to the common on one switch, two traveller wires connect the traveller terminals on the two switches, and the common on the other switch goes to the load. The exact way this is accomplished can vary depending on where the power feed is connected. It would be helpful to know how many cables come into each box and which wires from each cable connect to the switch.

 

[bjochman]

The switch at the top of stairs has black from power in (14-2 wire) going to common on 3-way switch. *********** in and white from 14-3 wire are wire nutted together. The red and black from the 14-3 are going to the "travelers" on the 3 way switch. The other 3 way switch downstairs (that isn't turning anything on or off) I have the black on the common and the white with the black tape and the red on the "travelers". No other wires in this box.

 

[bjochman]

Did this work correctly at one time?

Not sure, like this when I got it, tried replacing switch thinking that was the problem.

 

[mrb]

wait so the second box with the switch that doesnt do anything only has three wires in it, black white red? It sounds like the wires exit the working switch, go up to the light you cant get into, then back down to the non working switch. At the non working switch, use red and black as the travellers and put the white with black tape on the common.

heres detail of what I think is going on:
-power in to working box on 14/2 black, white=neutral
-14/3 exiting working box goes to light fixture. white = neutral, black and red are the travelers to the non working box. This cable goes up to the light fixture. At the light fixture the white neutral is connected to the light. The black and red are spliced to black and red of another 14/3 that goes back down to the non working switch. The white taped black is the common from that switch to bring power back up to the light fixture.

 

[bjochman]

I think that is what is going on, I will try the white with the black tape on the common tomorrow. Thanks for your time.

 

[nehog]

Which switch did you replace? It could be either switch, the one that seems to work could be defective causing it to appear that the other switch is bad.

 

[bjochman]

I replaced both 3 ways with working switches, same issue and those switches worked on the working circuits. I tried the white with black tape on the common still same results. I'm guessing I'm going to have to get at the can light somehow and see what's going on in there. Is there any other test I can do with a meter for what the three wires in the non-working switch box should be reading with power on or off? Like stated above, power is coming into upstairs switch then going to can then back down to non-working switch

 

[bjochman]

alright looking online another help forum said to tye the know hot and traveler together to find the traveler in the other box. Did this and confirmed that red in the 2nd box is a traveler. Then put the hot to the second traveler and got nothing on either of the remaining two wires. I'm assuming from this there is a bad connection in the can causing my problem. Now I have to figure out how to find the wiring in a can that is over a stairwell and i can't get to the top....

 

[Jim1]

Switches could be fine. Could be that your light has lost it's neutral.

 

[bjochman]

I fixed it today. It was in the wiring in the can. Thankfully the can wasn't too bad to get out of the ceiling, so all is well. Thanks for all your suggestions.