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AssuredElectrical
AssuredElectrical, Master Electrician
Category: Electrical
Satisfied Customers: 4241
Experience:  Contractor-42+ Years in the ElectricalTrade
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Having trouble with a three way switch. No apparent shorts

Customer Question

Having trouble with a three way switch. No apparent shorts (including a reading to ground). No apparent voltage either. Breakers are good.
Submitted: 1 year ago.
Category: Electrical
Expert:  AssuredElectrical replied 1 year ago.
Welcome. My name is ***** ***** would be glad to assist.
Please provide the details on the situation.
Were the switches wired and operating, then something took place?
Need the sequence of events so that information may lead which direction we need to proceed.
Thanks
Customer: replied 1 year ago.
Sure. There were older standard switches in place (this is a hallway). My wife and I attempted to replace them with the more modern looking flat switches. Normally not a problem. We've done other single switches in the house, as well as another hallway with three way switches with no problem. These light switches seem to be tied into a strange configuration as unwitting them has effected an outlet in the hallway, our stairwell lighting to the basement and an adjacent bathroom fan/light.
Expert:  AssuredElectrical replied 1 year ago.
Ok, thanks.
Sounds like more wires were disconnected than what was attached to the switches.
What is the count of wires in each of the boxes, along with the wire colors.
Then what wires are connected to each of the 3 way switches?
Call them Switch #1 and Switch #2 for easy posting.
So as an example of what one could be:
Switch #1
2 cables
One with black,white and ground
One with red,black,white and ground
Red and white from 3 wire cable connected to switch
Black from 2 wire cable connected to switch
white from 2 wire cable connected to black on 3 wire cable
Just an example of the details needed
Customer: replied 1 year ago.
Switch #1
Has two sets of cable, top and bottom.
Top cable has 1 black, 1 white, 1 red, 1 ground.
Bottom cable has 1 black, 1 white, an one ground.
The white wires are tied together. The grounds are tied together.Switch #2
Has one cable, with the following wires:
1 white, 1 black, 1 red, 1 ground.
Expert:  AssuredElectrical replied 1 year ago.
Ok, thanks.
Wired as it is,with the 2 whites tied together, there are not enough wires.
Were the wires inside the box disturbed? That is how it appears at this time.
Do you have a 2 lead voltage tester with readout display?
Can you drop the ceiling fixture the switches control to access the wires if needed?
Customer: replied 1 year ago.
Currently nothing is connected...
Expert:  AssuredElectrical replied 1 year ago.
Ok,
Thinking on the possibilities, the original wiring may be a little different than normal. Lets assume this since the wiring dictates no other options at this point
Do you have a 2 lead voltage tester?
Customer: replied 1 year ago.
I do have a multimeter. And I made a long jumper if I need to go between switches.I should also add that my wife said she initially wired the new switches exactly as the old switches...which did not work.nthis was also why I have attempted other wiring configurations.Standing by if you would like me to test or read something.
Expert:  AssuredElectrical replied 1 year ago.
Yes, be sure the ground wires are connected to each other at the box with the 2 cables.
Then go to the box with one cable and measure--one lead to ground and one lead to the white
Be careful and not touch the white with your fingers,when you turn on power
Customer: replied 1 year ago.
A few hundred mV when reading white to ground.
Customer: replied 1 year ago.
12M ohm. If it matters.
Expert:  AssuredElectrical replied 1 year ago.
Ok,
12m ohm?
That is not a voltage test.
That is continuity.
Need to set the meter properly and test a receptacle that works now with a lamp or appliance and see if you read 120 volts.
Set meter for AC voltage, the squiggly line
Customer: replied 1 year ago.
No no. With power on I only read a few hundred mV. Just gave you the continuity for more info.
Expert:  AssuredElectrical replied 1 year ago.
Ok,
test a receptacle that works now with a lamp or appliance and see if you read 120 volts.
If so, test every wire in the first box to ground and see if you find only ONE with power?
If not, you will have to drop the ceiling light for inspection, the wiring is loose and we need to see what or which one.
Customer: replied 1 year ago.
Meter checks out good on a known working outlet.
No power found on any wires at the #1 box.
Expert:  AssuredElectrical replied 1 year ago.
Ok, thanks
If not, you will have to drop the ceiling light for inspection, the wiring is loose and we need to see what or which one.
Customer: replied 1 year ago.
Wiring in the lamp looks good.
Expert:  AssuredElectrical replied 1 year ago.
There is a loose connection, we need to inspect all wiring to find the location.
How many wires and all the colors in the light box?
The black wire on the light fixture connects to which wire in the light box? Follow the wire and find the cable to see if it is a 2 wire cable or 3 wire cable.
We will start there and move forward.
Customer: replied 1 year ago.
Light box has 2 red, 2 black, 2 white, and 2 ground.
Grounds are tied together and then tied to the lamp ground.
Blacks are tied to each other.
Reds are tied to each other.
One of each white goes to the lamp.Black wire from the lamp fixture goes to a white wire coming from a cable in the light box. Both cables in the light box have 3 wires (black, red, white).
Expert:  AssuredElectrical replied 1 year ago.
Ok, thanks.
Based on the wiring, the 2 wire cable at Switch #1 is the main power for the light.
So, at switch #1, disconnect the 2 white wires that are together and then use the tester between the black and white wire and see if you read anything.
Maybe your grounds are disconnected somewhere and will not give us a good common point.
See if that black and white show 120 volts, POST the EXACT voltage found.
Customer: replied 1 year ago.
I've disconnected the two white wires, I am measuring the bottom cable white wire to bottom cable black wire is 2.075 volts. Then the top cable white wire to bottom cable black wire is 0.476 volts. Top cable white wire to top cable black wire is 0.649 volts. Then the top cable white to bottom cable black wire is 0.500 volts.
Expert:  AssuredElectrical replied 1 year ago.
Ok, only needed the one reading on the 2 wire cable. That is the power cable.
What is near the switch? Is there a receptacle?
Or any other switch boxes?
Test the receptacles in the area, you may also have one or more dead right now also.
If you know the circuit breaker for the light, turn it off and see if that 2 volts goes away.
if it does, then find every other item on that same circuit breaker so we have a list of possible locations.
Customer: replied 1 year ago.
With the breaker for the light turned off, 2 volts does indeed go away.Here's the strange part... There is one and only one, outlet nearby and it's in the same hallway as this lamp run by the switches we are attempting to fix. Before any of this began, that outlet was constantly powered. NOW that this problem is occurring, that hallway outlet only turns on if our bedroom light switch is on, (bedroom is at the end of the hallway).
Customer: replied 1 year ago.
And with that, I must apologize. I need to pause here for the evening. I look forward to your next response. If there is more information you require in the meantime, or would like to present me with the next step, please do so and I will get back with you tomorrow evening. Thank you for your assistance and troubleshooting up to this point.
Expert:  AssuredElectrical replied 1 year ago.
Ok,
So with the bedroom light on, does the 2 wire cable in that switch box have power?
Sounds like wires crossed in the bedroom switch, probably 2 black wires on one screw but the wrong one was ganged and should be on the other screw.
Thats a guess, need to check it to determine.
Customer: replied 1 year ago.
Good evening. I have done a bit more troubleshooting and rewired the bedroom switch. The bedroom switch now operates the bedroom lights appropriately, the hallway outlet is now constantly on (as it should be, as it was before), and the lights in the stairwell to basement now work as they did before.
I still don't seem to have power at the switches in the hallway.
I WAS able to use a jumper from another power source (hot) to the hallway switches (common) to get the lamp to illuminate.
Expert:  AssuredElectrical replied 1 year ago.
Ok,
Since other areas have had the switches changed also, there are too many possibilities at this point, as the situation is about the hallway switches now, it is about another location that is actually the issue.
Anytime you change any wiring int he home, the first rule is to go and check everything else in the home to be sure you have not interrupted power.
This keeps you form backtracking through the entire process when a single item doesn't work.
This what you need to do, it will save time.
Using the breaker that you found that controls the hall way light which has only 2 volts, you need to make a map of everything you can find that is on the same circuit.
Then you have the options of where that cable in the switch box may come from for power.
In this situation, it will require to start pulling switches and possibly receptacles out and checking wiring in each of them one at a time to find that point.
It sounds like there is still a possibility it may be in that bedroom switch box that now has the hallway receptacle working.
Or the hallway receptacle itself since the lights are in the hallway.
Below is how I do a map, so you have an overhead view of the situation and it is easier to see what is closest to the hall switch.
But it is a start, as you now have to back track to find the point the power was disturbed.
Link to directory mapping of circuits.
http://tinypic.com/r/2mp0b69/8

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