My situation is as follows: I am installing a new circuit that includes a 3-way with the fixture in the middle. I had to stop in the middle of the 3-way installation, after having run the 14/3 from the first switch to the fixture. To check my work (especially the power feed into the first switch within a 3-gang box), I tested the fixture wires and the black read hot at 120V. I then connected the light and it did not work. Thinking the fixture might be the problem, I tested the contact point for the bulb and it also read hot at 120V. My next step was to use an alternate fixture and, of course, my bulb, and I got the same results. I'm stumped, since I cannot understand how a bulb won't work when 120V is running through to the contact point. I can only assume that it has something to do with a 3-way switch with the second switch missing, or perhaps I am missing something else really obvious. Can anyone please help?

 

Well, you didn't actually tell us how you wired the first switch. Nor did you tell us how you measured 120 volts (between what two wires--you said the black read 120, but a voltage test must always be made between two points) or what test instrument you measured it with. Fill in these details and we can help sort through the myriad of possible explanations.

Properly wired, this should have worked, even with the second 3-way not there yet.

 

John, in response to your follow-up questions: For the feed into the first switch, the black wire in a 14/2 is running to the common via a pigtail, since the 14/2 is also powering another 3-way and a 4-way within the same switch box. I then ran a 14/3 from the switch to the fixture, with the red and black wires being attached to the travelers. Within the fixture box, as mentioned, I attached the black from the 14/3 to the black fixture wire and the white from the 14/3 to the white fixture wire. The red from the 14/3 is currently unattached and capped with a wire nut. I used a multimeter to get a reading between the black wire and the bare ground wire in the 14/3.

Thanks for your assistance.

 

Where is the white wire of the 14/3 connected in the switch box? It sounds like it is not well connected to the other white wires in the switch box. This would answer the question about why you can have 120 volts to ground on the hot wire but no power between the black and white.

 

John, the white/neutral issue hit me just before I fell asleep, but I didn't have the energy to get up and check. With the 3-gang set-up, I have 5 neutrals within a single wire nut. The wire nut has capacity for five 14 gauge wires, and I tugged at each neutral when I first installed it, but it is of course possible (and it now seems likely) that one or more came loose when tucking the bundle into the box. In fact, a couple of days ago I started thinking that I should separate the 5 neutrals into two wire nuts with a pigtail between, as I have had some trouble in other boxes with 5 wires in a single nut. It's a 55 cu in switch box, so there is a fair amount of space left.

I'll give it a closer look when I get home tonight. Thanks for the feedback.

 

Use a larger wire nut.

My personal preference is never to reuse a wire nut. I find that once it is fully tightened, it may not grip as well if you remove it and put it back on again.

 

First thing is there should not be a power feed to a 4way switch. But if it is working leave it alone.
Second thing is where is the 2nd 3way? The black and red from 1st switch should not be connected to the fixture. They should go on to the 2nd 3 way via the red and white wires and the black from 2nd 3way should be connected to the fixture.

 

I was perhaps a little loose with my terms. When I mentioned the 4-way, I meant the first of three switches in my 4-way switch sequence. To be more precise, the feed is to the 3-way, which then runs to the actual 4-way switch.

As for the second 3-way in the switch that is troubling me, it is located after the fixture. I plan to hook things up the way you described. My issue arose when I was testing my progress before running the 14/3 to the second 3-way. In other words, I was trying to operate the light with only the first 3-way connected and couldn't get it to work. I will be finishing the project this weekend (hopefully).

 

Using a larger wire nut would require that I or my wife go back to Home Depot for the 20th time in the lest few weeks, and I am absolutely sick of that place and their poor advice. Of course, however, you are absolutely correct that I should do this right and not choose an option simply to avoid another trip to the store.

I appreciate the comment on not reusing wire nuts. I had assumed that the threads within the nut dug into the copper wire and would not be affected by use or reuse.