I have a house (Georgia, USA) and some kitchen renovations have revealed some prior electrical work and I am trying to figure it out. Originally, there was a ceiling box in the kitchen with a fan/light fixture controlled by a pair of 3-way switches. One 3-way switch was located at the kitchen entrance to the garage and the other switch was located in a 2-gang box that it shared with a 2-way switch for a ceiling light in the dining area. The fan and light did not have separate switches.
At some point in the past, an exterior flood light was added to the house and the 3-way switch in the 2-gang box was replaced with a duplex switch. One switch controls the light fixture and the other controls the exterior flood light. The 3-way switch at the garage entrance was abandoned and covered with a cover plate. And by abandoned, I mean the 'electrician' bent back the tabs on the switch and shoved the entire switch into the box). The overall layout looks like this:
While renovating the kitchen, I found that the fan was mounted to a shallow fan-rated box with wiring from it to a second non-fan-rated box that was just laying on the insulation in the attic. I removed the ceiling fan and the boxes (mentally noting how it was all wired) intending to rewire it (using a properly sized single box) the following day. Due to circumstances beyond my control, the work was delayed several weeks and I cannot remember the exact wiring. I spent a couple of hours with my multimeter checking continuity to determine which wire was connected to what and I think that the kitchen ceiling box and 2-gang switch box looked something like this:
The 2-gang switch box on the right is exactly as I found it. The wires from the 3-way switch were sitting at the back of the box, unterminated with bare conductors exposed. The neutral was connected to the black unterminated pigtail with a wire nut as shown.
The ceiling box on the left is how I think it should be wired, with one exception. Note that there is black tape shown on the neutral going to the sink light switch. This switch is not a 3-way switch so I think that the black tape is a mistake. The hot from the ceiling box goes to the switch which then sends it to the light fixture. The neutral from the light fixture should connect with the neutral from the ceiling box in the switch box and all the neutrals are connected together in the ceiling box as shown.
Having said all that, there are three parts to my question:
- Does the ceiling box wiring look correct (taped neutral notwithstanding)?
- Should I remove the tape from the neutral?
- Can I replace the 2-way duplex switch with a 2-way/3-way duplex switch and reconnect the 3-way circuit? If so, how is the 3-way switch wired at each end? If not, how do I properly abandon the 3-way cable at each end?
My current plan is to implement the answer provided by A. I. Breveleri with the minor change recommended by RedGrittyBrick to make the constant hots black and the switched hots red. So the final result, if I'm not mistaken, will look like this:
If there are no objections, I'll wire it up this way and mark A. I. Breveleri's answer correct after the lights are on.
Also, in working on this problem I visited many sites that attempted to explain 3-way switches, but the only explanation that made the light bulb go on in my head was here:
"What is common in the diagrams above and with any 3-way switch circuit is that the power hot wire coming into the circuit will always go to the common terminal of the first switch. The hot wire from light always goes to the common terminal of the second switch. The traveler wires go from switch to switch connected to the traveler terminals, it doesn't matter which. As long as you keep this in mind, a 3-way circuit becomes really simplified. And of course the neutral will always go directly to the load."
Best Answer
I think you want to leave the kitchen box alone and rewire the 2-gang box like this. I used blue for the white neutral wires:
I followed the color scheme of the existing wiring, with the red carrying unswitched hot in the 3-wire cables. Please remember to mark the white traveler with black tape or paint.
You can re-use the duplex you have, but you might want to buy two new three-ways. You could straighten the tabs on the abandoned one but you have to go to the store anyway.
I sent the power to the further three-way first instead of to the one in the gang box because it saves one wire-nut.