I'm using the same Honeywell Programmable Timer from my last question, but under different conditions. In particular, I'm replacing a 3-way switch on 2-wire cable.

Here is a schematic showing the back porch light, a 3-way switch located in the garage, and a 3-way switch located in the house:

General Overview

And here is a closer inspection of the switch (demarcated by green):

enter image description here enter image description here

  • What does the wiring at the other switch look like?
    – Tester101
    Mar 26, 2015 at 19:42
  • 2
    In the last photo where you have the timer "working", it appears that you have the grounded (neutral) from the timer connected to the ungrounded (hot) conductor from the circuit. Trial-and-error wiring is almost never a good idea. If you don't understand the basic concepts of wiring, and/or can't follow simple wiring diagrams, you should probably not be doing this type of work yourself.
    – Tester101
    Mar 26, 2015 at 20:05
  • 2
    At best, replacing a 3 way switch with a 2 way switch that requires a neutral will result in a setup that doesn't work correctly. At worst, you'll create a short circuit that could damage devices on that circuit, electrocute yourself, or start a fire. So as tester101 says, if you don't have the knowledge to understand this mistake, you shouldn't be working on wiring in your home. Get professional help.
    – BMitch
    Mar 26, 2015 at 20:10

1 Answer 1


You'll have to purchase a timer that is specifically designed to work as a 3-way switch. Or you'll have to rewire the other 3-way switch in such a way that it will no longer control anything.

Since I can't see the wiring at the second switch, I'm guessing the wiring currently looks something like this...

enter image description here

Which is sketchy, since there's no grounded (neutral) conductor running with the travelers. It's not clear where the grounded (neutral) conductor that the light is connected to comes from, so you'll want to look into that.

To get this timer working, you'll have to bypass the other 3-way switch like this.

enter image description here

Again, I don't know what the whole circuit looks like, since you've only offered a partial look. So I'm guessing at the wiring when it comes to the second switch.

  • Returning it for a 3-way timer seems most appropriate.
    – metabind
    Mar 26, 2015 at 22:34
  • Even with a 3-way, I'm slightly concerned with the lack of grounded (neutral) conductor.
    – Tester101
    Mar 26, 2015 at 23:57

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.