DIY Home Improvement Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1
hello,

i'm replacing 2 3 way switches that both control two hallway lights. the old switches are very outdated, but i'm having a problem with the new ones.

i can get them both hooked up to turn on/off the lights, but when one switch is off, the other won't work. i don't know what's going on.

in the first box the black wire is the hot, which i attach to the common. then the red and white are travelers and w/out power.

in the second box, the black has no power, and the red and white are powered.

i've tried every combination on the 2nd box and can't get it to work correctly. the old switches weren't grounded to the box. could it be something w/the new switches?

thanks!
 

·
Super Moderator
Joined
·
21,126 Posts
Grounding has nothing to do with the switches not working. You have the wrong wire on the common at one or both swithces.
 

·
Registered
Joined
·
77 Posts
Follow these steps if you can.

Separate all 3 wires from each switch, find the only hot wire. Between the 2 switches only one will be hot if wired correctly.Put that hot wire on the common. If using Decora style switch, look very closely for the common, it fools many!

In the same switch box put the remaining 2 wires on the remaining screws on the 3 way.

At the other switch location - wires sticking out of box -only one wire will now be hot,that will be a traveller. At the previous switch turn the switch to the opposite postion. A different wire will be hot back at the other switch location, this is the second traveller. The remaining wire in the switch box will be your common.

If using an inductive type tester that may be giving you a false reading, test hot to ground if possible. Good Luck!
 

·
Registered
Joined
·
14 Posts
Discussion Starter #4
thanks uncleduey, i believe i can follow your steps.

although, when both switches are off of the box altogether, and the wires are sticking out of the box and the power is on, box 1 has 1 hot wire. box 2 has 2 hot wires. i thought box 2 would be dead until getting power from box 1?
 

·
Super Moderator
Joined
·
21,126 Posts
It should be be. What are you using to test for power? A digital meter? It could be a false reading. Did you disconnect the neutral from the feed line as well?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #6
no, i'm not using a meter. i used on of those indicators that beeps when there is electricity nearby. i put it on the lowest setting and touched all 3 wires. in the 2nd box, 2 wires beeped indicating they were hot. in the 1st box, 1 wire beeped indicating hot.

is this wrong?
 

·
Registered
Joined
·
2,294 Posts
in the first box the black wire is the hot, which i attach to the common. then the red and white are travelers and w/out power.

in the second box, the black has no power, and the red and white are powered.
Simple.

In the second box, the black is common.



The power comes from the first switch to the second on either the red or white wire depending on the position of the switch.

The second switch sends that power to the fixtures in the same manner.
 

·
Registered
Joined
·
84 Posts
You guys who know this stuff flat-out amaze me. :laughing:

Electricity has always been a bit of a mystery to me. I've learned to do the basics, and I can figure out some of the more complex things pretty well given a good book and a lot of patience, but it's never come natural.
 

·
Registered
Joined
·
1 Posts
3 way switch

you are using the wrong type of tester those voltage "detectors" are only made to sense the magnetic field from AC current, they will usually beep if any wires in the box are hot and sometimes from a voltage imbalance on the neutral wire. Which means the wires you think are hot are not. You need to use a "contact" type tester and touch one lead to a wire and the other lead to ground (or neutral)

Be careful, you could have done the same thing with the power off using a continuity tester to find whih wires are travellers, leaving the commons as the last to hook up.

Remember a dead circuit NEVER killed anyone :eek:
 

·
UAW SKILLED TRADES
Joined
·
5,341 Posts
Please describe the wiring in each switch box. Something in my opinion is missing.

For example is there only one cable coming into each switch box with a red,white and black wire plus ground or is there more than one cable in a switch box beside the 3 wire with ground cable ?
 

·
Registered
Joined
·
14 Posts
Discussion Starter #13
Please describe the wiring in each switch box. Something in my opinion is missing.

For example is there only one cable coming into each switch box with a red,white and black wire plus ground or is there more than one cable in a switch box beside the 3 wire with ground cable ?

box 1: 1 cable entering with a ground wired to the box: black, white, red

box 2: at least 2 cables entering with a ground wired to the box: brown, white, and red
 

·
Super Moderator
Joined
·
8,939 Posts
It's all smoke and mirrors.


Well....smoke anyway.
Electrical devices are filled with magic smoke. When the smoke escapes it is time to replace the device.:laughing:
 

·
Registered
Joined
·
14 Posts
Discussion Starter #17
no, not a typo. they used a different color. it's close to black, but it's not black.

not sure what the second cable is. there are 2 overhead lights that these 2 switches control. could it be for the second light?
 
1 - 17 of 17 Posts
Top