Strange 3-way question

[marrt]

I have a house with a detached garage. When starting to add some insulation to the garage I removed a switch in the garage that controls an outside light above the garage door. Power for this switch is coming from the house. I was in a hurry and didn't notice this is a three way switch. That's normally not problem...however, the original electrician ran two standard 14-2 UF wires from the house to this switch and didn't mark anything. So, I have two black, two white and two ground wires coming from the house.

So far, I've identified the common and traveler wires and rewired the switch in the garage. It works fine from the garage and inside the house. With one problem...I have a wire left over. Since the electrician used two 14-2 UF wires instead of one 14-3, I have a wire in the garage (black in this case) that isn't connected to anything. Worse, when the house switch is in a certain position, this wire is hot (the switch in the garage doesn't affect this wire, as currently wired).

What do I do with this wire? Put a wire nut on it and push it back in the box?

 

[Mustang51js]

If everything is working fine then yes,just nut it and tuck it back. If you find out later you have no power somewhere then you know where to start. How did you test it anyway, with a non contact testor or with the leads

 

[justsam]

What other receptacles, lights, or garage door operators are in the garage?
Are you sure they are now all working?
A detached garage should only have one power feed, and a single 14-2 seems a little skimpy. Are there other circuits?
Are you sure the power for the light is being fed from the house?

 

[marrt]

How did you test it anyway, with a non contact testor or with the leads:
I used a Fluke non-contact testor to identify which line is hot and a multimeter to identify the traveler wires (wire nutted one end and checked the resistance)

What other receptacles, lights, or garage door operators are in the garage?
There's nothing else using this line in the garage.

A detached garage should only have one power feed, and a single 14-2 seems a little skimpy. Are there other circuits?
The underground service for the house actually comes into the garage. So I have two panels there. But they wired the light outside the garage from the house so they could turn it own inside the house, along with the other light on the 3 way. There are no other circuits in the garage fed from this line.

Are you sure the power for the light is being fed from the house?
Yes.

It bugs me that the unused line goes hot. I could see a scenario where the electrician had some 14-2 UF lying around and didn't want to go buy 14-3. But why connect the "unused" wire to anything?

Yet again I learn the same lesson over and over. Take pictures before and during dis-assembly of anything.

 

[cabranch47]

Sometimes the non-contact testers will pick up an induced or "ghost' voltage and give you a false reading. Check again with actual leads. I have come across this numerous times.

 

[Mustang51js]

Sometimes the non-contact testers will pick up an induced or "ghost' voltage and give you a false reading. Check again with actual leads. I have come across this numerous times.

That's what I was getting at, but if nothing is out and everything seems fine just wirenut it and tuck it away. Even if it doesn't have power it's still good practice to throw a wirenut on it anyway

 

[jdieter]

If you don't have a meter to check it, temporary in a lamp to the wire in question. Use anything you can find for a good ground, metal water pipe, grounded hole in a grounded receptacle, stick a screwdriver in the ground and attach the other lamp wire, etc. If the lamp illuminates then you know it's not induced voltage and you'll have to dig deeper in the wiring to disconnect it at it's source.

 

[Onewolf]

This is not at all what I was thinking of regarding a "strange 3-way" question.

 

[Elginz]

Check the switch in the house on the common screw should be a black from the power source. the other two screws would be the two black wires from the UF to the garage. The white wires would all be wire nutted together.
In the garage there should be a wire to the light fixture over the door, that black should be on the common screw, the two black wires would be on the other two screws. The white wires all wire nutted together. There is just an extra white (neutral) wire.
But you never know.

 

[soapii]

This is not at all what I was thinking of regarding a "strange 3-way" question.

Same thing I thought. Didn't know Garage Journal was a source for that type of information.

--Joe

 

[zmaxmotorsports]

If everything is working fine then yes,just nut it and tuck it back. If you find out later you have no power somewhere then you know where to start. How did you test it anyway, with a non contact testor or with the leads