# Troubleshooting two 3-way switch setups

Show 40 post(s) from this thread on one page
Page 3 of 5 First 12345 Last
• 11-23-2010, 01:27 PM
Thatguy
Jim Port
Electrical Contractor
This message is hidden because Jim Port is on your ignore list.
View Post
Remove user from ignore list

[So much for freedom of speech! :D I guess this comes under freedom of listening or not. . .]

I found it is much easier to predict the results given the schematic instead of the other way around, but I can't resist a good puzzle.
Quote:

Originally Posted by mgabbard
#1 down, #2 down - lights are on
#1 up, #2 down - lights are on

Taking only the case shown above, if you step through on a piece of paper all 3 ways of hooking up the 3 terminals of a working #1 switch to 3 wires and with switch #1 in both positions [6 diagrams in all] I don't see how this outcome is possible unless you have #22 wiring with 3 travelers.

An "impossible outcome" means that we are assuming something that is not true.
What's good about these is that we will probably learn something new. Plus, nobody else wants these budget-busters. :D

To find out what it is I'd say check #1 switch with an ohmmeter. If it checks good something has changed inside the walls and that's a separate troubleshooting procedure involving a voltmeter and incand. bulbs.

There are many different wiring diagrams for this, but I can only find two schematics. In any case it's a source in series with a load in series with an SPST switch made up of two 3-way and zero or more 4-way switches.
• 11-23-2010, 04:18 PM
Jim Port
How would something have changed within the walls? All the wiring should be in accessible junction boxes. If the box was buried there would be no way to make a change to it.

The example posted is the way that 3 ways work. There is nothing to troubleshoot.
• 07-21-2011, 04:59 AM
roncarter
Quote:

Originally Posted by Thatguy
This assumes two travelers between the switches.

Assign each switch a number.
With switch #1 & switch #2 down, light is on or off?
With #1 up & #2 down, light is on or off?
With #1 down and #2 up, light is on or off?
With #1 & #2 up, light is on or off?

In principle, with the answers filled in, the problem(s) can be pinpointed.

Test cases welcome. . .

1 dn 2 dn = off
1 up 2 dn = off
1 dn 2 up = on
1 up 2 up = on

I replaced porceline sockets (working properly) with can lights and found that I MUST have made an error, and now I seem to be missing the nuetral for 4 of the new lights. If I hook up a jumper wire from the nuetral at sw#1(where feed comes from) the 4 lights work but trips the breaker in one of the variations of switch configurations as follows:

1 dn 2 dn = off
1 up 2 dn = trip
1 dn 2 up = on
1 up 2 up = trip
• 07-21-2011, 06:05 AM
hj
Switch 3 is probably, but not necessarily, the miswired one, and there are several ways it could be miswired. One problem is that you would have to test switches 1 and 2 under ALL possible configurations to ensure that 3 is actually the misfit.
• 07-21-2011, 02:56 PM
roncarter
3 way switch troubles
I now have all 3 switches working so they can turn the lights all off and on, BUT... the bulbs (all same wattage) are dim. and if I remove any bulb, the rest of the lamps go off.
• 07-21-2011, 04:26 PM
DonL
Ron,

That will save you electricity, being wired in series.

Nice Job.

Have a Great evening.

DonL
• 07-21-2011, 07:10 PM
roncarter
Thanks DonL, but they aren't wired in series. At least not in what might be considered the "normal" series circuit.

It seems that one or more of them are 'hung' on travelers, rather than the neutral and hots. I have 4 boxes to go check to see where I hooked up wrong! All of the boxes are attached to the original ceiling joists 14" above the new 5/8FC ceiling, which obviously makes it very difficult to get to for troubleshooting purposes. I posted here to pick ya'lls brains about where I might start looking to possibly save some aggravation.
• 08-19-2011, 03:41 PM
Sinestro
Assign each switch a number.
With switch #1 & switch #2 down, light is on or off?
With #1 up & #2 down, light is on or off?
With #1 down and #2 up, light is on or off?
With #1 & #2 up, light is on or off?

off
on
on
on

The weird thing is, if the downstairs switch is on, then the upstairs switch can't turn off. Both on and off keep the light on.

This one has been baffling a friend and I for weeks. Any help would be appreciated.
• 08-19-2011, 08:11 PM
ActionDave
It would be my bet that the upstairs switch is not functional due to miswiring, bad switch or it just plain never worked.
• 08-21-2011, 06:46 AM
Sinestro
Quote:

Originally Posted by ActionDave
It would be my bet that the upstairs switch is not functional due to miswiring, bad switch or it just plain never worked.

The downstairs switch does the same thing though. Turn on the upstairs switch and you can't turn it off downstairs.

This all worked until we took down a wall and one of the other light switches
• 08-21-2011, 07:01 AM
LLigetfa
My very first electrical wiring was with two 3-way switches. I think I was around 10 or 11 at the time. My father couldn't figure it out and hired an electrician to help. Unfortunately the electrician couldn't figure it out either and while they were gone to buy more fuses, I took up the challenge.

It was so simple that I could not believe two grown men could not figure it out. I just followed the schematic on the side of the box the switch came in. Also, not having any more fuses, I just screwed a lighbulb into the fuse panel to test. Since it was in series, it was dim but had I got the wiring wrong, rather than blow a fuse, the bulb would be bright.

When my father and the electrician returned with the fuses, they thought I was pretty bright too.
• 08-22-2011, 09:06 PM
ActionDave
Quote:

Originally Posted by Sinestro
The downstairs switch does the same thing though. Turn on the upstairs switch and you can't turn it off downstairs.

This all worked until we took down a wall and one of the other light switches

Alright then. You have a miswired switch. Nothing more than a WAG but I bet the power came to the light first and after the remodel work a wire was crossed.
• 08-23-2011, 07:50 AM
Sinestro
Quote:

Originally Posted by ActionDave
Alright then. You have a miswired switch. Nothing more than a WAG but I bet the power came to the light first and after the remodel work a wire was crossed.

Apologies as I am a bit of a Luddite, but what is a WAG?
Also, I have read on here that you guys use a "light bulb test". What does that entail?
• 08-23-2011, 08:41 AM
jwelectric
Quote:

Originally Posted by Sinestro
Also, I have read on here that you guys use a "light bulb test". What does that entail?

Anyone who answers this question will have their post deleted.

Light bulb testers are death in a socket and unsafe advice will be deleted.
• 08-23-2011, 08:59 AM
nukeman
WAG = Wild A** Guess
Show 40 post(s) from this thread on one page
Page 3 of 5 First 12345 Last