OLD WHITE AND BLACK TWO WIRE WIRING DIAGRAMS INSULATED
White, Black and Red wire question | This Old House
Nov 01, 2011I'm installing a new light fixture in the bathroom of a house we are remodeling. It is a simple white and black wire fixture with the ground wire. The previous fixture had been removed before we took over. There are 2 white wires together, 2 black wires together and one red wire all capped off coming from the wall unit. One wall switch. I tried to wire it up in my typical way:Black and white wires both hot | This Old HouseJul 21, 2013Two Black and Two White wires for GFCI | This Old HouseJun 01, 2013GFCI outlet has 2 white and 2 black wires | This Old HouseFeb 23, 2012Both white and Black wire are carrying a load. | This Old House See more results
Old Light Switch with Red and Black connected, White is
Dec 07, 2010Original old house wiring was often red and black, with no white wire. So, what they probably did was make a connection with new wire from the breaker panel (red, black, and white) and tied it to the existing wire to the switch (so they didn't have to replace the wiring in the wall).Followers: 1Status: OpenNormally the neutral wire is not at the switch. The wire runs to the light first. The white wire is connected to the light itself. The black wire is run down to the switch without connecting to the light and connects to the switch. then the red wire is connected to the switch back to the light black lead. The switch provides a interuption of power to turn the light on and off. I'm thinking they dropped a 3 wire.(red, black, white) hence the white wire they dropped to the swicth is not used on the light or the switch. Could be alot of possibilites without seeing it but that is what comes to mind.Best answer · 2First of all the color code for wiring houses in the 1950's and today are the same! There is no red and black wiring (except for low voltage things like door bells, etc.)
Now it is possible that the circuit was part of a three way switch at some time in the past. Of course if this was the case the white wire would have to be changed to a different color by law (in all states). This didn't always happen.
There was at one time a cable for switch legs that contained 2 black wires and a ground but it wasn't very popular and has since disappeared (at least I haven't seen it in many years).
The most likely reason for your case is that whomever was wiring knew that it was illegal to have a white wire that was being used as anything but a neutral and decided (probably had an extra length of 3 wire and decided to use that) to just use the 2 colors that can be used for line out of a 3 wire cable.
Another thing might be that at some time another switch was there and one wire fed both switches and the returns were the other 2 wires with one light feed passsing through the box for the other light.
Try looking in the box where the light is. This may help explain things a little better (or not).
Good Luck!0Black Light Switch0In older homes, you'll find just about anything that the previous owner has done - none close to being safe or code compliant. Keep that in mind when you troubleshoot a problem.
The light switch only needs two wires. One wire carries power from the circuit breaker - this wire has full time power on it. The other carries power to the load (light) - only has power when the switch is closed. In today's wiring, the third bare wire is earth. Today, electricians I've seen cover the white (switched power) wire with black tape or paint it black to indicate that it is (or could be) hot. Handle with care. In your installation they used the black and red wires to send power to the light. My guess is that all of your outlets are 2-prong without a third grounding connection.
In today's wiring, a red wire from a switch goes to an outlet. That allows the switch to control power to the outlet that usually has a lamp plugged into it. Kind of like a remote control for the lamp. The black wire can also go to the same outlet but supplies full time power to the other side of the outlet. If you look at the outlet, there's a jumper between the two outlets. Break this jumper and you can control one half with a switch and the other has continuous power.0FYI: Just because a wire is white, doesn't MEAN it's a neutral. This is a common misconception. If you have black, red and white wires, you could have a three way switch. It's possible that one of these wires (white, since it's cut and taped) is damaged somewhere down the line. Instead of spending the money to fix the problem, the previous home-owner "put a band-aid on a broken leg", (sorta speak) I don't know just how your house is laid out, location of switches, etc.. It's just when I hear about a wire being taped off then another switch that has all three connected, it leads me to believe that you're dealing with a three way. USUALLY, the black is the "common", while the red and white wires are the "travelers". Hope this helps. Good luck in all you do and may God bess.1That's the problem with amateur do-it-yourselfers who owned the house before you redoing some of the electrical in a house. It made sense to them at the time, but you have no idea what they did to make it work.
Original old house wiring was often red and black, with no white wire. So, what they probably did was make a connection with new wire from the breaker panel (red, black, and white) and tied it to the existing wire to the switch (so they didn't have to replace the wiring in the wall). And, now it's anyone's guess as to whether the red or black wire is the hot or neutral.
If you have a volt meter, you can open a nearby outlet that has the black/white or red/white wires, and then take voltage readings to see which switch wire is hot (if you measure hot to neutral, you'll get 120V - if you measure hot-hot or neutral-neutral, you'll get 0V).2