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Time switch has 3 wires, box has 4. How do I wire?

Posted by keviv (My Page) on
Thu, Sep 16, 10 at 18:28

Hi all,

I wanted to install a timer switch for my bathroom exhaust. I picked up one of these at Home Depot: Leviton Timer Switch 6161T.

The issue is that the old switch had 4 wires connected to it, while this one only has 3 wires coming out of it. (The old switch is just a plain old on/off switch.)

On the new switch, I successfully connected the hot and the load (both were black), and the ground wire (green wire to bare wire).

The remaining wire just runs from the original switch, to another on/off switch next to it, which controls the bathroom light.

What do I do with that wire on the new switch? There is nowhere to connect that on the new switch. I tried just taping it up and leaving it in the back, but when I reconnected everything, none of the lights in the bathroom worked. I was able to reconnect all 4 wires on the old switch and get it working again.

Any idea how to make this new switch work? What can I do about the extra wire?

Is it possible that extra wire is a neutral wire? Why would it just run from switch to switch? Note, I did also see white wires inside, from the line side, and the two load sides. They were all just connected to each other with screw connector, and not connected to either of the original switches. White wires are usually neutral right?

Note that the instructions for the new switch say "a neutral connection is not required for this device".

Appreciate any help!


Follow-Up Postings:

RE: Time switch has 3 wires, box has 4. How do I wire?

The wire that runs from the one switch to the other switch is the power feed in wire. I don't know what the other wires are.
Your old switch had two terminals and the green ground. Connect all the wires from one terminal to the hot. Connect all the wires from the other terminal to the load connection. Connect the green/bare wire to the ground connection.

RE: Time switch has 3 wires, box has 4. How do I wire?

Thanks joed,

What does a 'power feed in wire' do? I tried googling that but only got results about how to feed wires through the wall...

I'm fine with the rest of the wires, already had them connected properly. But until this extra wire (power feed in wire) is taken care of, it seems like none of the lights/outlets in this bathroom will function.

Anyone have any ideas? As I said, the new switch doesn't have any place to connect this wire.

Thanks joe and thanks all!

RE: Time switch has 3 wires, box has 4. How do I wire?

Pictures. We need pictures.

You probably have to pigtail the "power feed wires", or LINE wires, leaving one tail to connect to the switch. Just because the new switch does not have a dedicated spot for it does not mean it does not belong there.

RE: Time switch has 3 wires, box has 4. How do I wire?

Sorry but if you don't know what a power feed wire does you need to call an electrician.

RE: Time switch has 3 wires, box has 4. How do I wire?

Okay, not sure I'm following. Here are some pictures...
Click on them to enlarge!!

Picture 1: the outside view

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Picture 2: the back view, with wires labeled

Image and video hosting by TinyPic

Picture 3: Inside view, to illustrate the white wires, not connected to the switches, but just capped off with the yellow cap.

Image and video hosting by TinyPic

Click on any picture to enlarge.

So, anyone have any idea what that mystery wire is, and what to do with it on the timer switch which only has a line, a load, and a ground coming out of it??


RE: Time switch has 3 wires, box has 4. How do I wire?

Ignoring the ground wires(since you know where they go) I can't be any clearer than this. You have two terminals(the part where you push the wire in next to the screw terminal is the same terminal, maybe that is your sticking point?) on the old switch. Let's call them line and load. The line terminal is the one with the 'mystery' wire. The load terminal is the other one. Take All the wires on the load side, marrette them to the load Side wire on your new device. Take the wire from the other terminal, marrette it to the other wire on the new device. Ta-da!

RE: Time switch has 3 wires, box has 4. How do I wire?

Your line has to go to both switches, that's what the mystery wire does. It just continues the line from the first switch to the second.

RE: . white wires

The white wires are not just capped off. You need a continual line from the panel to the fixture for the neutral. That is what the yellow cap is for, to join two lines to make them one.

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