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Wayne Roberts
Wayne Roberts, Electrical Technician
Category: Electrical
Satisfied Customers: 81
Experience:  Electrican 6+ years
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I have a question about wiring in my parents house. They

Customer Question

Hello. I have a question about wiring in my parents house. They have an old house with the old wiring with cloth covering. Not knob and tube a little newer but not by much. They have a 3 way switch in the dining room and it worked earlier today until I said I could change out the dimmer that wasn't working, thinking it would be like newer wiring but when I went to hook it up it didn't make sense. I checked all of the wiring. The dimmer box has 2 lines coming in white & black which are the 2 hot wires coming from the fuse box. There is also 3 other wires in the same box. One white, one black and the other looks reddish. The other box is a switch and has 2 wires which I assumed went to the light fixture and the other 3 have a black, white and reddish wire. I assumed that I would plug the switches in like a normal 3 way but then realized the light wouldn't turn on when setup this way and when I tested the lines up to the light with no switches attached and just the wiring connect the lights didn't turn on. I then decided to take the switches out of the equation to see how the wiring was connecting. I connected box 1 blacks together and the 1 red to black and the whites together. Then box 2 I connected the whites together and blacks together but connected the red to white and now the light turns on. It appears that the reds go to the light. I assume this is because the light fixture also has other wiring attached which means the hot wires are also providing power to the upstairs as there are 3 whites and 3 blacks connected in the ceiling but taped and the 2 reds come out and connect the fixture. I need to know which wires I need to reconnect in each box for the 2 new 3 way switches. One is a 3 way dimmer and the other is a regular 3 way switch. I thought I had it as the dimmer works and the switch works but if I turn off the switch the dimmer turns off. Hope this makes sense to someone and can help. I am only here for the night and early am tomorrow and wanted to get this fixed for them before I left. Thanks
Submitted: 1 year ago.
Category: Electrical
Expert:  Wayne Roberts replied 1 year ago.

hello, my name is ***** ***** i would love to help you get this 3 way switch figured out :)

Expert:  Wayne Roberts replied 1 year ago.

You determined that in box 1 you had a black and white from the panel and a black white and red. Are these all the wires in box 1?

Expert:  Wayne Roberts replied 1 year ago.

may i have pictures of the electrical boxes and splice points?:) this will help me help you.. also, what manufacturer and model dimmer do you have?

Customer: replied 1 year ago.
Thanks for the quick response. These aren't the best pics because if I pull out the switches the lights go off. The dimmer is a leviton rotary dimmer 3 way and single pole option. It has 2 reds and a black. The one red is the traveller I assume and is insulated and says don't remove unless you want to do a 3 way. I have the other red plugged into red leading to the light and the black is plugged into the white. I may try to draw you a diagram of how the wiring appears to me if that is easier. The other box has a standard 3 way switch. If that switch gets turned off then the dimmer turns off and isn't usable. If the switch stays on then I can use the dimmer and turn it off and on without issue.
Customer: replied 1 year ago.
Please see attached diagram. It shows the dimmer box with a black and white hot wire which comes from the basement fuse panel. The whites are attached to each other and the blacks are attached to each other. The red connects to one wire on the dimmer and the white is attached to the other. The red from the dimmer box appears to go to the left side of the light fixture. The other box has 2 wires, black and white which appear to go to the light fixture but they are taped at the fixture. The box also has the same 3 wires, black, white and red. The Red is connected to one pole of the switch and the black the other. The blacks and whites are also connected in this box. Ideally the light switch can turn the light off and on as well as the dimmer. Maybe I have it connected properly but the dimmer will only work when the light switch is in the on position?
Expert:  Wayne Roberts replied 1 year ago.

i am guessing you dont have a multimeter.. did the 3 way switch function correctly from both locations before the old dimmer failed?

Expert:  Wayne Roberts replied 1 year ago.

From the box with the panel feed the hot wire(black) should go to the black terminal. and the black and red from the black red white bundle should go on the gold screws. The whites together. In box 2 the black wire from the light will go to black on the dimmer, the black and red from the "black red white" bundle will each individually go to the red wires coming off the dimmer. Whites together. This is a typical 3 way set up

Expert:  Wayne Roberts replied 1 year ago.

if that does not work you will need a multi meter.

Expert:  Wayne Roberts replied 1 year ago.

hey boss, were you able to get the three way dimmer working?:)