Need Help With a 3-Way Switch

[Skeezix]

I have a local utility box mounted on a wall inside the front door. It contains a single pole switch (#1) that controls a light outside the front door. The box also contains a 3-way switch (#2) that, together with a third 3-way switch (#3) some distance away, controls a light inside the front door. All switches have worked normally for the past 35 years.

In this description I won't talk anymore about switch #3 or its wiring because it is in a remote utility box and I have not removed its striker plate.

I was going to replace switch #1 with a timer switch but while I was doing that the wife came in and read me the riot act and after that my mind went to mush. So now I'm in the process of putting everything back together the way that it was to start.

The Setup

1. Five romex cables enter the local utility box. Each romex cable has a black, a white, and a ground wire coming out of it. Two of the five romex cables also have a red wire coming out of them.
   
   
2. One romex comes from the circuit breaker behind the house. A second romex leads to the light outside the front door. A third romex leads to the light inside the front door. The fourth and fifth romex lead to the receptacles in a room on the other side of the wall.
   
   
3. The grounds from all five cables are tied together in a pigtail inside the box. A bare wire from the pigtail goes to switch #1 and #2 ground connections.
   
   
4. The white wires from four of the cables are tied together in a pigtail. A fifth white wire comes out of one of the cables that contains a red wire. That white wire goes directly to a terminal on switch #2.

Here is a drawing from Electrical 101 that shows how 3-way switches are wired:

​

The Problems

a) In the attached diagram red wires are connected to the the switches but in my setup there is no continuity between the red wires, so I don't know where they go.

b) The stray white wire was connected to switch #2 but I can't remember where. If I recall correctly, there were two black wires connected to the single-pole switch.

c) One of the black wires goes to the recptacles in the other room but I can't remember which wire.

d) I have no idea which of the black wires is connected to the circuit breaker and it will be a big job to pull all of them out of the utility box to test. The 3-way switch has no markings showing where the Load and the Line terminals. It just has the word "Common" at the terminal with the red wire.

I know this is a big can of worms but I hope somebody here can help me out.

 

[Guzzle]

Finding out where each wire goes [hot, neutral, ground, switch wiper or other terminal, lamp or nowhere] is tedious.
Figure a morning to do this.
You'll need a VOM & two incandescent bulbs [one for the outside light] & a known good ground & clip leads.

 

[Skeezix]

Here's what I'm working with.



It will take time to figure out where the main power input is, and then figure out if it comes from the circuit panel or from the remote 3-way switch. Not shown is the single-gang switch.

The wires are not very long so I have to be pretty judicious about cutting them to isolate them. My main concern is where the red wires go, since there is no continuity between them, and where the loose white wire goes.

 

[bud16415]

Not that it will help you now, but always take a cell picture before and or label the wires and make a sketch.

Sounds like you can eliminate most of the wires doing other things and concentrate on the 3way wires. Do not cut any wires in the process. Turn off power unless you are checking for voltage.

Good luck.

 

[Guzzle]

Here's a schematic, not a wiring diagram, of what you want to find out.
The "A" indicates one of three possible locations of the neutral connection.

120v source ….A…..switches…A……lamp….A
|………………………………………………....…|

 

[Guzzle]

My mistake.

120v source ….N…..switches………lamp….
|………………………………………………..…|
or
120v source ….N…..lamp……….switches….
|………………………………………………..…|

 

[Skeezix]

UPDATE:
Over the last two weeks I have managed to recall how the 3-way switch was wired. I wrote it down and will rewire the switch when "...I get around to it."