3 way light switch issues

Chizl · 04-24-2011, 08:41 PM

I had a house built and recently, I've been putting ceiling fans in each room. Once I got outside on my back porch, I noticed that the Light switch was putting out 64volts, while it was off. The fan switch worked fine. I went and checked both switches and it was always 120v or 64v, no matter which way it was flipped. The light switch had is on a 3 way switch.

I called the home builder and they sent someone out who gave me this spill that someone had run hot wires to both switches and had the traveler running across, which was causing the issue. He said he capped the hot wire off the secondary switch and it should be working now. I, for some reason, took his word for it and left it as is. I've been busy so it's been a few week, so when I went up to test it to find, It doesn't work the way it was, but in a more weird manner.

Now if I turn both the light and fan off from the primary, both wires are not hot, thats good. When I turn them both on, both are 120v. However, if I turn 1 on and the other off, the one that is off will have 64v, while the one on is 120v. No matter which one I turn on, if the other is off, it does this!!

What the hell. How does one switch change the voltage in another switch that isn't part of the 3 way? They just sit side by side, thats all. I've verified that nothing is touching, so I'm a bit confused, but I'm not an electrician either, so I'm in the dark.

Saturday Cowboy · 04-24-2011, 09:24 PM

your 64v is what we call phantom voltage. There rest sounds like it was fine and he messed it up

Chizl · 04-24-2011, 10:17 PM

Is it supposed to be there, this Phantom voltage? Because it was there when he got there, just in a different way now. I figured the fan would run at half speed, if I turn the light on, but not sure, is why I ask.

Saturday Cowboy · 04-25-2011, 12:09 AM

Digital Multi Meters can in some cases show voltage where there is none, switch loops is one spot that they show up.

Lets start with a better description of the situation. How many switches are there and where. Then if you pull off the covers how many cables enter each box. from there we will be able to tell you how it should be hooked up.

Chizl · 04-25-2011, 02:11 AM

I have 1 switch by an outside door from the master into the back porch, this one is for the light and has a red, black, and white wire going to it. I have two switches by the sliding door in the living room, the one on the left is has two black wires only going into it. This is my fan switch. Why they put the fan on the left and the light on the right is beyond me, but I can flip that myself. On the right, is my 3 way switch. It has 2 red wires and 1 white wire. The white wire seems to always have 64v coming from it, one of the red wires has 64v coming from it, when the bedroom light switch is flipped one way and 120v when the bedroom light switch is flipped the other way. The one in the bedroom is the only one that has the copper ground on it, not sure why they didn't put it on either of the switches in the living room.

Chizl · 04-25-2011, 11:08 AM

I want to make this a normal switch. Can I tie the black and red together from the bedroom switch and cap that off? Then go and do something in the livingroom that makes that 3 way work like a normal switch or do I have to buy a normal switch to do that?

Want to make sure I'm by passing the switch in the bedroom correctly.

Saturday Cowboy · 04-25-2011, 04:46 PM

well this is all wired wrong. lets fix it then we can be sure of it working correctly when you remove the switch

Saturday Cowboy · 04-25-2011, 05:01 PM

this is all romex? in the switch box with two switches how many cables enter th box?3?

First thing we need to do is determine which cable is the home run. to do this disconnect all wires and measure voltage to ground on all wires. the cable that has power when everything else is dead is our home run. (white wires maybe be used as hots here) This home run is our king neutral and king hot. The following makes some assumptions so if it is not like your installation please advise. else: The king hot must be spliced to both switches, on the three way switch it must be landed on the black screw. in the cable to the fan from the 2switch box, one wire will control the fan this wire should also be landed on the fan switch(and all grounds made up). There should be a cable that directly or indirectly goes from three way switch to three way switch. in this cable in the double box the white wire and red will be our travelers, (the white should be marked to indicate so) these travelers will attach to the other two screws on the three way switch. in the same cable the black wire is our switch leg, the switch leg will be spliced to the wire to control the light. now in the other switch box, the black will land on the black screw and the travelers on the others. now back in the double box the king neutral must be sent to the fan, splice it to the white wire headed to the fan.

If at any time this is not clear or more info is needed, come back here and we will be glad to hold your hand if needed