# 4 way switch troubleshooting



## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

Are there any Brains out there that want to tackle this question. According to my manual and video I watched I thought I wired my 3 and 4 way switches correctly. I have two 4 way switches between two 3 way switches. 

This is what happens: when all the switches are flipped up nothing works?? 

When the last 3 way switch is flipped down the two middle 4 way switches and the first 3 way work?? 

When the last 3 way is switched up the two middle 4 way switches don't work but the first 3 way does??

Thanks for any help you can give me..


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## Wildie (Jul 23, 2008)

You should tell us if the power goes to the light first and then is fed to the switches or if the power goes to a 3 way switch first.
There are two variations and its important to know which one that we are dealing with!


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## joed (Mar 13, 2005)

We need to know which switch or the fixture that the power feeds into. We need to know which switch the fixture is fed from.


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## Yoyizit (Jul 11, 2008)

DOITRIGHTTHEFIRSTTIME said:


> Are there any Brains out there that want to tackle this question. Thanks for any help you can give me..


SW #1 is first 3 way
SW #2 is first 4 way
SW #3 is second 4 way
SW #4 is second 3 way.

0 = SW down
1 = SW up

X = light on
- = light off

Please fill this in

switch..light
#........on?
\/\/.......or
...........off?
1234.....\/\/

0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111-
:thumbsup:

So in your case, 1111 [all switches up] has the light off [I think] so you put a dash under the light on/off column.

Is "don't work" the same as "off", or the lamp just stays the way it was?


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## frenchelectrican (Apr 12, 2006)

Also double check the format on the fourway switch there is two patterns it will hook up { it depending on the manufacter set up }

And if you get the 4 way switches from big box store sometime you will end up getting double pole switch instead of 4 way outside both look the same but inside it is not.

This what I do for troubleshooting the 4 wayers by pass them by using wire nuts and start work on each three ways once you get them working right then deal with 4 wayers last this will really cut down your headaches.

As I mention above the 4 wayers only have two tries depending on which manufacter it is once you know the pattern with first four wayer then do the same with the next one and it should work slick.

Merci,Marc


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## 220/221 (Oct 9, 2007)

> when all the switches are flipped up nothing works??
> 
> When the last 3 way switch is flipped down the two middle 4 way switches and the first 3 way work??
> 
> When the last 3 way is switched up the two middle 4 way switches don't work but the first 3 way does??


This means nothing.

The cable path and wire colors mean everything.

Path is 3way, 4way, 4way, 3way



Hopefully your *power* comes into one of the *3way* boxes.

Hopefully you have 3 wire cable going from box to box.

The question is, which box does the switch leg cable go in to? Hopefully, one of the 3 way boxes.


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## frenchelectrican (Apr 12, 2006)

220/221 said:


> The question is, which box does the switch leg cable go in to? Hopefully, one of the 3 way boxes.


 
That I hope also if the power do come in one of the 4 ways that will really raise the "fun" factor of 100. { plus few cussing along the way }

Merci,Marc


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## Yoyizit (Jul 11, 2008)

I still have hope that, with just what the OP posted it can be narrowed down to a single switch, once the Truth Table is filled in.


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## RenoDon (May 4, 2009)

OK, pay attention. You should have 3-wires plus ground from switch to switch black, red, white, and a 2-wire black and white going from one of the end switches to the lights, and power at the other three way. If this is not the case let me know, I can still help you. 
Assuming the above senerio attatch the blacks and reds to the travelers on the 3-ways and make sure you connect the the black and reds on the 4-ways to line in and line out in other words line in would be the black and red from one of the 3-wires and line out would be the other 3-wire. All the whites connect together as do the grounds. The power source will connect to the common terminal of one of the 3- ways and the switch leg, the black going to the lights will connect to the other 3-way on the common terminal.
Good luck


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## 220/221 (Oct 9, 2007)

> I still have hope that, with just what the OP posted it can be narrowed down to a single switch, once the Truth Table is filled in.


My brain does not EVEN operate that way.:jester:

I thought you were just mesing with him.


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## RenoDon (May 4, 2009)

Yea its still possible th wire it no matter wher the power comes in.


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## hayewe farm (Mar 15, 2009)

Just a guess, but it sounds like you have one traveler hooked to the load/power screw and the light/power wire hooked where the traveler should be on one of the three ways


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## RenoDon (May 4, 2009)

Could be, but you won't know untill you pull all the switches out and verify everthing.


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## joed (Mar 13, 2005)

Until the OP comes back with the info asked for there is nothing to do. One or more of the switches is wired wrong.


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## Yoyizit (Jul 11, 2008)

220/221 said:


> My brain does not EVEN operate that way.:jester:


It shouldn't. 
Mine does because I had to work with binary circuits and all that, and this is a binary [two-state] circuit.

The truth table for two 3-ways is easy.

00 X
01 -
10 -
11 X

Where X can be light off or light on 
and the - can be light on or light off.

If you add a four way sw. the table is 8 rows long, and two 4-ways gives you 16 rows.


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## renoet (Feb 12, 2009)

I would make sure that one of 3way switches have hot leg, and the other 3way have switchleg that goes to light. Make sure you got your two traveler wires going between first 3way, through two 4ways. and end up to last 3way switch. Like Frencelectrician suggests, bypass both 4way switches by connected wires with wirenuts. Then make sure you got your 3way switches right by using right terminals on the switch. after that install your 4ways. Good luck


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## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

Wow! 
You guys are great! Sorry for not getting more info back sooner. The power is coming into my first three way and it feeds my exhaust fan from there. I have 4 switches that feed this exhaust fan, The first 3 way and the two middle 4 ways work perfect when my last 3 way is in the down position. I really do appreciate all of your efforts and will try every one of them if need be..

God Bless!


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## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

Thanks Yoyizit,

I would need a little help in rewiring my brain to understand what you are trying to explain to me. I am all for black and white truth tables. Hopefully a light will go on in my head to grasp this..


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## Yoyizit (Jul 11, 2008)

DOITRIGHTTHEFIRSTTIME said:


> The first 3 way and the two middle 4 ways work perfect when my last 3 way is in the down position.
> 
> I think there are two faults present.
> The wiper [instead of one of the stationary contacts] of your last three way is connected to one of the travelers, and the travelers at the last three way seemed to be shorted together, maybe inside the switch.
> ...


My light is burned out, the truth table killed it. . .:laughing:


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## joed (Mar 13, 2005)

Sounds like you hav ethe wrong wire onthe common of the last three way. The wire inthe common of the last three way should not connect to anything between the first box whre the fan is and the common terminal. It should feed through both of the 4 ways with no connection to the switches.

You only have two more tries to get the right wire on the common.


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## Yoyizit (Jul 11, 2008)

I can't come up a schematic that would account for your symptoms.

Unless someone's already come up with this, here's another approach. 

Working with only the first and last switch, confirm that alternately flipping each switch makes the light go on twice and and off twice. 

That is, starting with both switches down and 
the light either on or off, 
flip #1 up and 
then #2 up and 
then #1 down and 
then #2 down. 
The light show go on and off with each switch flip. 

The center two switches should be in whatever position it takes to make this happen.

Does this work?


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## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

Yoyizit said:


> I can't come up a schematic that would account for your symptoms.
> 
> Unless someone's already come up with this, here's another approach.
> 
> ...


 Yes, it works fine this way. If I have last 3 way down,1 4 way up, 1 4 way down and 1st 3 way up I can shut fan off from all locations and turn it on and off from the two 3 way locations but cannot regulate the fan from the 4 ways???

Thanks again for everyones help!!


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## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

joed said:


> Sounds like you hav ethe wrong wire onthe common of the last three way. The wire inthe common of the last three way should not connect to anything between the first box whre the fan is and the common terminal. It should feed through both of the 4 ways with no connection to the switches.
> 
> You only have two more tries to get the right wire on the common.


I have the white as a common throughout and is not tied to anything until the last 3 way.

Thanks


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## DOITRIGHTTHEFIRSTTIME (Dec 22, 2008)

renoet said:


> I would make sure that one of 3way switches have hot leg, and the other 3way have switchleg that goes to light. Make sure you got your two traveler wires going between first 3way, through two 4ways. and end up to last 3way switch. Like Frencelectrician suggests, bypass both 4way switches by connected wires with wirenuts. Then make sure you got your 3way switches right by using right terminals on the switch. after that install your 4ways. Good luck


 Thanks, 

It seems like the 4 ways are simple because I have a red and black and a red and black and they are installed correctly and the white is the wire nutted wire through out the system and goes into my last 3 way. My confusion is more because everything appears to be wired correctly but doesn't work?? I don't think it is a bad switch because they do operate the fan depending on what position some of the other switches are in. Can a bad ground be a cause of anything??


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## RenoDon (May 4, 2009)

It's not a ground problem. If you believe everything is correct try switching around one set of the black and red wires on one switch. This will usually fix the problem. Why? I have no Idea. I have only had this happen a few times over the years.


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## Yoyizit (Jul 11, 2008)

DOITRIGHTTHEFIRSTTIME said:


> 1 4 way up, 1 4 way down
> 
> turn it on and off from the two 3 way locations


Just explaining this is confusing.

I have stepped through, on paper, every way of wiring the two end switches, and I don't believe they can cause your symptoms by themselves. 

Furthermore, I think the two end switches are wired correctly, assuming you checked all four switch positions.

It seems the 4-ways are only acting like travelers when they are in certain positions, instead of all the time [when the end switches are being switched and the 4-ways are not being switched].

I recommend removing one 4-way, and in its box, wirenutting an incoming traveler with an outgoing traveler and then doing the same to the other traveler, as if the switch is replaced with a through cable.

Then, step through all 8 combinations of the three remaining switches [3 switches with two positions is 2³ = 8] and see if they work properly.

The light should change each time you flip a switch according to this Gray Code truth table: 0 is switch lever down, 1 is up.

000
001
011
010
100
101
111
110

While the 4-way is out of the circuit, check it.
Label a switch terminal "1". 
Find a terminal that has continuity to 1 and label it "2". Label the other two terminals 3 and 4 and check that they have continuity and 
that there is no continuity between 1 & 3.

Flip the switch lever: 
if there is now continuity between 1 and 3 there should also be between 2 & 4 and none between 1 & 2.
or
if there is now continuity between 1 and 4 there should also be between 2 & 3 and none between 1 & 2.

In use, 1 & 2 replaces a traveler and 3 & 4 replaces the other traveler.


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