Troubleshooting two 3-way switch setups

Discussion in 'Electrical Forum discussion & Blog' started by Thatguy, May 7, 2009.

  1. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,971
    Location:
    NW Ontario, Canada
    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.
  2. ActionDave

    ActionDave Electrician

    Messages:
    346
    Location:
    Colorado
    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.
  3. Sinestro

    Sinestro New Member

    Messages:
    5
    Location:
    Va
    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?
  4. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Anyone who answers this question will have their post deleted.

    Light bulb testers are death in a socket and unsafe advice will be deleted.
  5. nukeman

    nukeman Nuclear Engineer

    Messages:
    711
    Location:
    VA
    WAG = Wild A** Guess
  6. Sinestro

    Sinestro New Member

    Messages:
    5
    Location:
    Va
    Oh lord thanks. Is there a safe way to test out which wire is which? I have no idea which wire is which.
  7. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    3,971
    Location:
    NW Ontario, Canada
    Does that include my little pocket screwdriver with a neon bulb in the handle one end of which is wired to the tip and the other end to the pocket clip that touches the hand?
  8. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Most untrained people who dabble in electrical work should never use a meter for any reason. Let me repeat, most untrained people who dabble in electrical work should never use a meter for any reason!
    What most people don’t understand is that the meter they hold in their hand is one of the most dangerous tools they have

    Most people as well as a lot of trained electricians think that the fuse in a meter will protect them from harm. In 99.9% of the cases the fuse only protects the current function of the meter. See the drawing on the meter in the posted picture.

    Meters come with a category rating marked on the meter. For testing voltage in a 240 volt panel with a maximum short circuit of 25ka and a fault clearing time of .033 second I will use nothing less than a category IV meter. After I am about 30 feet from the service disconnect (this is measured along the path of the conductor) I will drop to a category III meter. The meter must have a rating of at least category II for me to check the voltages on switches and receptacles. A meter rated at category I can be used by the electronics tech as I won’t use one.

    ANY METER THAT HAS NO CATEGORY RATING GOES IN THE TRASH INCLUDING NON-CONTACT AND LIGHTED METERS!!!!

    The one thing I can promise is that once one has been involved in a flash over their respect for electrical energy will change, mine did.

    I have said for years you can tell when someone knows what they are doing by looking at their tools. The use of meters tells me just how qualified someone is doing electrical work. I have turned many away just because of their meters.


    [​IMG]
    Last edited: Aug 23, 2011
  9. Sinestro

    Sinestro New Member

    Messages:
    5
    Location:
    Va
    Boy thanks I appreciate the warning! Which brings me to my next question. Since I am unqualified to do this, about how much does it normally cost to troubleshoot and fix 3way lighting issues? I want to make sure I don't get fleeced. Thank you again for your help.
  10. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    The best way to answer that question is to say, as much as the market will bear.

    The hourly prices will as much as $25 different within 50 miles radius of where I live.

    If I am paying an electrician $30 an hour it will cost me over $40 an hour to give it to him. Therefore I must receive at least $55 an hour for that man to come out with a profit.

    Any service call I go on will waste at least half a day so if I don’t get at least $250 for that service call I am going broke real fast.

    It will cost as much as you are willing to pay.
  11. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
  12. ActionDave

    ActionDave Electrician

    Messages:
    346
    Location:
    Colorado
    I can't tell you how much the job will cost, but I can tell you that if you find an established electrical contractor that has been around your area for a good while and has good references the price will be fair. Most of these guys do not have the biggest add in the Yellow Pages.
  13. Nita Younger

    Nita Younger New Member

    Messages:
    1
    Location:
    New Jersey
    Lighted 3-Ways

    Hello All, I am up late obsessing about what I must have done wrong: I just replaced 7 switches, all lighted. As I finished up I noticed one of the switches wasn't lit & isn't working at all. There are 2 3-ways in that box. All the blacks twisted & wire nutted with pigtails (I'm assuming those are the 'Common'. All the Whites & Gnd's also wire-nutted. I added pigtails to ground the switches. BTW there was nothing wrong with the switch I replaced; I was just replacing them all after the downstairs 3-way shocked - there was a bad nick in the common.

    So here is my diagram:

    With switch #1 & switch #2 down, light is = off
    With #1 up & #2 down, light is = on
    With #1 down and #2 up, light is = off
    With #1 & #2 up, light is = on

    This is a 1974 Bi-Level, at the front door are 2 3-way switches controlling 2 lights - 1 entry & 1 downstairs hall. At the bottom of the stairs are 2 switches (1 3-way) controlling the downstairs hall & a room. At the top of the stairs are 3 switches (1 3-way controlling the Entry) & 2 single poles controlling other lights.
    I assumed the switch was bad & replaced it, no luck. I then rewired in 3 different ways, no luck. My neon tester shows the wires are hot. But I agree with jwelectric in that those other testers scare me to death. At least now I know why - lol.
    Thanks

    Update,
    Fixed now. Found an old simple continuity tester, shut of the circuit breakers, with the clip on the black screw (in switch #2) both travelers were on. Finally dawned on me that the problem wasn't in switch #2 - sure enough a traveler & the common were switched in switch #1.
    Last edited: Sep 5, 2011
  14. mestanton11

    mestanton11 New Member

    Messages:
    2
    Location:
    Wisconsin
    Tricky problem

    I am trying to figure out a couple 3-way switches for which the wires are routed peculiarly through conduit buried in concrete. In switchbox 1, I have 6 wires, 2 black, 2 white, blue and red. One black is the hot, the other black and one of the whites go to Light 1. The blue and red are travelers. The old switch was wired so Light 1 black was wired onto the post with the blue traveler.
    The second switch (I have no idea of the route the wires took to arrive there) contains the blue, red, white, another mysterious hot black and another black and white to Light 2.
    Maybe something like this:
    ___W____________________________________
    l l
    O [S2]======R/blue==i=[S1]---Hot
    L1 __B___l l l
    B l lW
    O L2
    O is light, B is black, W is white.
    S1 had black wire to light pigtailed to blue traveler wire.
    S2 had blue wire jumped to black light wire. I figured out the juice could travel to both lights that way. Unfortunately, if switch 1 is flipped to blue, light 1 is always on. I must be missing something. It did work correctly before I took it apart. There are 2 circuits in switchbox 2 which I separated. There is also in that box an extra white wire. I don't know which one belongs to which circuit. Sorry for lame picture.
    Thanks for any help or references.
    Picture is screwed up by posting. Sorry. Basically light 1 is wired through switch 1 and light 2 is wired through switch 2.
    Last edited: Dec 29, 2011
  15. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    In order for a three way switch to work it must be wired correctly.

    Each switch will have one screw that is marked with the word “common”. Sometimes this screw will be darker color than the other brass looking screws
    The common screw will ALWAYS have either the supply (hot) or the switch leg (the wire going to the light). The common of one switch gets the supply while the common of the other switch gets the switch leg.

    The other two screws are travelers between the two switches. There should never be anything connected to these screws but the travelers which goes from one switch to the other. They do not get pigtails of any kind nor are they wired to any other wire.

    The neutral is always connected so it is not switched. I like to teach that the neutral goes straight to the load with wire nuts.

    There is no way to wire two lights to a set of three way switches where one light is connected to one switch and the other light is connected to the other switch.

    I beg your forgiveness but I can’t make heads or tails out of this.
    ___W____________________________________
    l l
    O [S2]======R/blue==i=[S1]---Hot
    L1 __B___l l l
    B l lW
    O L2

    When you figured that you could light the second fixture by jumping the hot to a traveler you also figured out that this just won’t work the way you want it to work.

    The two conductors going to the two fixtures (switch legs) will need to be connected together in order for the two switches to turn them both on and off at the same time. There is no way to control both lights by jumping from the common to the travelers.
    Last edited: Dec 30, 2011
  16. mestanton11

    mestanton11 New Member

    Messages:
    2
    Location:
    Wisconsin
    Well, that's where I got stuck. I've wired quite a number of 3-way switches in my time, but this one is a poser. It did work, before I took it apart. Thanks for responding.
  17. rgrovier

    rgrovier New Member

    Messages:
    1
    Location:
    California
    Going crazy!

    Going crazy ... Appreciate any comments or advice anyone can provide. Here's my situation:

    Had: 2 sets of 3-way switches on 1 breaker as follows:
    Set 1: Stairs - Dimmer at bottom, Rocker switch at top. Installed Lutron Maestro Dimmer/Companion set. No problem.
    Set 2: Hall - Dimmer by bedroom, Rocker switch by stairs. Tried to install Lutron Maestro Dimmer/Companion set. Can't for the life of me get it to work. Even exchanged with the set installed in Set 1. No change - the run that worked continued to work (therefore not the switches). Tried to go back to 3-way Rocker switches at both ends thinking I would "dumb it down" and then go from there. Can't get them to work.

    Here is where I'm at with the Rocker switches: Diagrammed the up/down results as follows:

    Starting with Both Down, lights are OFF.
    Change Switch 2 to UP, lights ON.
    Change Switch 1 to UP, lights remain ON.
    Change Switch 2 to Down, lights remain ON.
    Change Switch 1 to Down, lights turn OFF.

    In a second test:
    Starting with Both UP, lights are ON.
    Change Switch 2 to Down, lights are ON
    Change Switch 1 to Down, lights turn OFF.
    Change Switch 2 to UP, lights are ON.

    In a third test:
    Starting with Both UP, lights are ON.
    Change Switch 1 to Down, lights are ON
    Change Switch 2 to Down, lights turn OFF.
    Change Switch 1 to UP, lights are ON.

    This is the way it looks using the schematic first posted in this thread:
    Down/Down - Off
    Up/Down - On
    Up/Up - On
    Down/Up - On
  18. Kevin S.

    Kevin S. New Member

    Messages:
    1
    Location:
    Pennsylvania
    Here's my situation. Any thoughts?

    Off
    On
    Off
    On

    Thanks!
  19. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,121
    Location:
    Houston, TX

    Short Between the headsets ???
  20. firecap04@gmail.com

    firecap04@gmail.com New Member

    Messages:
    3
    Location:
    Toledo
    I have an issue...probably overlooking something easy.

    i replaced 4 lights controlled by 2 three way switches. The issue is that one switch does nothing at all. The other works fine.
    Could it be as simple as a bad switch or can I have wires crossed?

    Thanks!
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