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Mike, Master Electrician
Category: Electrical
Satisfied Customers: 1425
Experience:  Licensed Master Electrician - OnQ Certified Data Voice Audio Video Installer
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I have a 3 wire romex with and red wires hot which im trying

Customer Question

i have a 3 wire romex with white and red wires hot which im trying to connect to a 2 wire romex which is attached to a light
JA: Thanks. Can you give me any more details about your issue?
Customer: i cant wire it up so the light works
JA: OK got it. Last thing — Electricians generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Electrical
Expert:  Kevin replied 1 year ago.

Hello and welcome to Just Answer. My name is ***** ***** I will be happy to assist you with your electrical question.

Can you provide some additional details as follows?

1) Does power (circuit feed hot & neutral) originate at the wall switch box or at the lighting box?

2) What type of wall switch controls the light? A single pole switch with 2 wires or a 3-way switch with 3 wires?

3) Do you have either a 2 wire lead AC voltage tester or an AC voltmeter available?

4) Does the light always stay ON or is the light not working?

Customer: replied 1 year ago.
1; wall switch
2; a 3way switch
3; no (?) I have a "pen" that lights up if i touch a hot wire
4 light is not working
The switch has power (red white and black wire were connected to the light switch) but does not operate anything so I pulled a 2 wire romex in the attic to a new light fixture and am now trying to get the light to work
Customer: replied 1 year ago.
new light, new 2 wire, running to the switch. Switch is hot (red and white wire))
Expert:  Kevin replied 1 year ago.

Thank you for the replies.

1) At each of the 3-way wall switches, what are the wire colors that terminate to each of the brass screws?

2) On a 3-way switching circuit, there needs to be 3 wires terminating to each switch. Is this what you have?

Customer: replied 1 year ago.
No other switches seem to have an effect on this switch red and white stay hot even if I toggle the one other switch that doesnt seem to do anything. But yes it has 3 wires terminating also
Customer: replied 1 year ago.
red and white on the traveler and black on the common
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

1) If power is originating at one of the switch boxes, the white neutral wire is required to be fed thru each 3-way box and extending to the light box. Can't use a white wire as a traveler if the power originated at the 1st 3-way switch box.

2) Refer to the diagram shown below:

3) Is this a brand new installation? Both switches and the light are new or is this an existing installation?

Customer: replied 1 year ago.
i dont know where the power originates from/if that other switch is connected to this one. It is an older home and came with the wiring as is.. was trying to install a light fixture tapping into the switch that doesn't seem to do anything.
I found the diagram you sent online and have tried to connect according to the diagram but I obviously don't know if the wires feeding it are wired correctly.. I assume they are..
Customer: replied 1 year ago.
I am assuming wiring was done when they refurbished as they took out walls and re-did some stuff that looks professionally done)
Expert:  Kevin replied 1 year ago.

Thanks for the replies.

1) Any idea if the 3-ways were wired prior to the 1960's?

Customer: replied 1 year ago.
definitely not. No knob and tube.. house was built late 80'ies was a showcase efficient home at the time
Expert:  Kevin replied 1 year ago.

OK, reason I was asking about the age was that prior to the 60's it was somewhat common to wire 3-way switches as either Carter or California switched which is a more complicated method as compared to the diagram I sent you.

Since the home was built in the 80's, the 3-ways should have been wired as shown in the diagram as this is the most common method.

You will require either a 2 wire lead AC voltage tester (a contact type) or an AC voltmeter to confirm the functionality of the existing wires. Pen testers sense voltage based on inductance and can easily provide a false indication since they can pick up voltage from other wires within a box.

You should have a 3 wire Romex running between the two 3-way boxes. And a two wire Romex feeding the circuit hot and neutral to one switch and a two wire Romex at the other 3-way box that extends to the lighting box. Just like the diagram illustrates.

Customer: replied 1 year ago.
I'm closing the question and getting an electrician to come in and check it all out before my house burns down :)