Video Links here>> California 3-Way - kzfaq.info/get/bejne/d8uIechmzM7Re4U.html Standard, Dead End and Single poles Switches here>> kzfaq.info/get/bejne/eJyXmaxomLral2w.html

Retired Electrician, Worked around the Washington DC area and fixed a few of these in older homes. We called them "Lazy Susans." Met my wife on a service call to repair one, I was the third electrician she called, everything was pulled apart for the remodel. First two walked away insisting there was no way that it had worked before. I bet her dinner that I could fix it in 20 minutes (4 gang box of switches). We had Pizza - she paid.

We bought an old house in 1981 and I, a young guy knowing the rudiments of residential knob and tube, was rewiring a 3-way on our stairs with romex when I discovered a light fixture off but both terminals hot. After calling my father, we tried to draw it out but failed. Then we called my grandfather, a longtime lineman for the regional power company. He drew it out for us and, as I remember, it was just as shown here. I've wired up numerous houses over the years but have never run into it again. Thanks for a great video.

This could not have been explained clearer or better. Nice work!

The same circuit was also used in Germany (of course it is also not allowed anymore nowadays). We call it the "Hamburger Wechselschaltung" Which would translate to the "Hamburg three way". I find it funny that you also name that after a city. But here it was also not only done in Hamburg. I remember whitnessing my Grandpa getting an electric shock from one of those things when he was changing a lightbulb which was turned off at the time.

About 15 years ago I ran into something similar and my boss at the time got mad at me for not being able to figure it out and make the repair. I've been through school in both the Navy and an accredited DOL-certified vocational school and now I'm a licensed electrical contractor and I'm still baffled lol. Great explanation through and I guess it's good that I dont understand it because its a dangerous way to wire lighting and receptacle circuits. Great video!!

This was not the video I was looking for when searching "Chicago 3 way", but I watched anyways.

I work in Chicago, I've run into this once every year. It amazes me that this problem is still out there.

Retired electrician. I have run across several of these 3 ways. Usually they don't have power run between the switches. Instead, switch 1 gets power from receptacle 1 and switch 2 gets power from receptacle 2. This worked OKish when we had single phase 2 wire services, but when you upgrade to 3 wire 2 phase electric services, you could have the switches on different phases and send 240 volts to the bulb. I knew this as a farmer's 3 way. I learned about them early in my career and made money fixing them when other guys were confused.

When I was a kid puzzling out how electrical systems worked (based on my experience of wiring up a train set), this is what I came up with for the 'magic' of three way switches. I thought it's how they all worked until I came across my first standard three-way, which was very confusing to me at the time based on my Chicago assumptions from childhood.

In 30 years of doing electric work I've 8:02 only seen this one time in an old knob and tube home we were rewiring. My boss at the time called it a switched neutral 3 way and showed us how it actually worked. Very cool to see you describe it with such great detail.

I've watched a lot of three-way videos, and this was by far the most informative!

Wish you’d been my apprenticeship instructor 45yrs ago. Great explanation! 👍🏻

This reminds me of lamp cord replacements. I've seen several with the polarity switched, leaving the screw shell hot all the time, including when the lamp is off. Always good to do a continuity check to make sure the screw shell is connected to the wide blade on the plug.

First, thank you for your service, fellow Air Force. Electrician for 40 years, never heard of this dangerous situation.

This is KINDA ingenious in that it makes the XOR operation by inverting the lampholder polarity for the two ON states and double-hotting or double-neutraling it for the OFF states. Back when I studied the topic, this was not even given as an option. We were taught straight off to make the "hallway switch" by wiring hot to one switch, connecting the switches through the travelers, then taking the lamp hot from the other switch. And in a 230V country I can readily see why this was not even an option.

This principle is used in some bidirectional power converters, as well as solid-state on-off controllable AC switches - unlike triacs which you cannot turn off before the next zero crossing. Simple, yet effective.

Well done! Bravo! I have tanfled with these before and it took me a few hours to figure it out. I have also seen solid CU MC using the metal cladding as the traveler, once. That lit me right up!

As an 11 year old kid, I learned from turn of the (last century) self teaching books. In high school shop my teacher started hollering about codes and rules. I have to see the remaining styles. You do a GREAT job. Switching Neutrals since 1959, my new moniker.

I work on many older homes in Chicago. I am currently (pun intended) ripping into my 1914 home with layers of insanely bad wiring. I've got one 'circuit' somewhat like this. I've got a degree in EE, and figuring this place out is insane. I've got a Klien ET450 tracer and am shocked (yes, pun) at where someone(s) ran lines over the years.

This is both brilliant and kind of terrifying! If I ever find myself a homeowner again, I'll be sure to be aware of this setup!

There were a few light switches in a house I worked on that looked like that, but I didn't know that what it was called. Thanks for the information.

As an apprentice, I found this video really helpful. I've dealt with knob and tube before, though I've never seen a three-way switch in such homes. Now I do! 😊

We had that in our old (1912) family home, BUT SW1 was powered from a fuse box in the basement, and SW2 was powered from a fuse box on the second floor! Another problem occurred when we replaced one of the switches with a 3-way dimmer switch- the new dimmer switch immediately failed, it was apparently make-before-break and shorted the power ! That would not be a problem with today’s wiring methods.

Thanks for the upload, guess it was worth the wait. Didn't realize this was known as Chicago 3 way, I'm assuming this method was designed by the Chicago Outfit to electrocute their victims instead of using a Tommy gun, which would draw more attention to authorities vs "deadly encounter with light bulb " lol😊 Joking aside, I actually ran across this 9 years ago on a farm in Sanilac County, Michigan. The farmer, who my father has known for many years, had 3 way switch in the house and barn on different panels, barn style yardlight on a pole near the barn, and single wire from the house and barn to the yardlight, installed sometime during early 50s, when the farm got electricity. The light sometimes got super bright for a couple seconds before going out with a bright flash that cracked the bulb, and the trouble began when the farmer purchased a 240 volt air compressor and needed to move some breakers around in the barn panel to make room for a 2 pole 20 amp, and unknowingly moved the circuit for the yardlight onto the opposite phase, and putting 240 volts on the light instead of turning it OFF in one of the four switch positions. Because I was 25 at the time and volunteered to try and figure it out while just beginning my apprenticeship, and explained to the farmer what he did in the panel and how I got it working normally after scratching my head for probably a couple hours, he took me out to dinner at a very fancy Italian restaurant. I personally found that very educational and rewarding to figure out with no help from anyone or any electricians books.

I'm rewiring all the circuits in my house and your channel has been very helpful! thanks!

Great explanation and diagrams. You explained so well that I saw that one coming! 😄

Very informative! Not an electrician, but I’m often asked to change switches and receptacles for building maintenance. Thanks for the video.

Extremely valuable information. Thank you

So far, this is your most important video I have watched. Thank you.

Excellent informative video - thank you!

Man, I remember as an apprentice when I first started working in residential electrical, I would always come across these Chicago and California three-way wiring methods. Very exciting💥😅 times for me back then.

That’s an interesting method. Thanks for showing it! 26 years in the electrical trade and I have never seen this. I have seen some knob and tube wiring that was switching the grounded side on single poles.

Good explanation. Thanks for sharing.

Excellent explanatiin on a scary situation on an older remodel, thank you.

Learned something new today , thank you very much 👍.

Thanks for posting this, I've been patiently waiting for this since you reply to me on another video. I believe Iran into this about 50 years ago at a relatives house , if I recall correctly there was power to the light fixture but it wouldn't light. I managed to change a faulty switch and got the light working but never really understood (or cared) about what was going on.

Great explanation, thank you! Looking forward to the explanation of the "California Three-way". Haven't heard of that one before watching your channel.

Excellent video and explanation. Thank You

I had one of these neutral flip 3 ways in my 100 YO house, it took me a bit to figure out what they did. You see this in old houses where the light fixture was always hot and then neutral flip modified with wall switches. As soon as I removed the bulb, I figured out what they did. It was old knob & tube wire, so they grab any available neutral source and run it to the lower light switch to save wire and time. They took neutral from the outlet to the lower switch, cutting & into the hall stairwell neutral at the fixture. Then added a switch at the top of the stairs tied to the nearest neutral, then down to the lower stairs switch and flipped neutral(s) to the fixture and abandoning the fixture old neutral wire. You can call that a MN neutral flip.

I have a rental property built in 1970 that had a "broken" 3-way in the kitchen. I thought the switches failed, but after replacing them I could never get both switches to work. I always used the standard method, but now I see that possibly they were wired via the Chicago method. I'm not familiar with the California method, but I'll look into that too. Thanks for the excellent tutorial.

Awesome and thank you. Actually this explains why a few years ago during a gutted upgrade of the kitchen in my historic home with tube and knob, I first got zapped and then -- after fixing the mistake I must have made despite attempting to label everything -- had 240V going to a light fixture. The polarity's were flipping depending on the switch positions.

Wow. This is amazing. Many years in the trade. Had no idea this method existed. You sir, have earned my subscription.

Fascinating, thanks for the explanation.

Back in 2005 was doing custodial/ maintenance work for my church's campus. The original wiring was done back in the '40's in the old dairy barn. It was patched together with mineral insulation and K&T. But it had one of the three way switches that just about drove me crazy. Because one switch was at the back door of the shop building 150' away and the other in the barn. On and it was run underground in 3/4" steel conduit. Like to never figured that one out.

Very nice video. Understanding it helps to correct to a code compliant method.

I have never seen this before, and I was in the trade for 40 years. But that was in New England. Glad, this could drive a man crazy.

Retired electrician, mystery solved. I have run across this 30 years ago in Denver, really never understood til now. It's always bothered me that I didn't understand, GOOD JOB!

Whoever came up with that had a lot of confidence in those switches enforcing break-before-make regardless of how slowly the child moves the handle. Twist-POP.

Thank you, great information! I'm a home inspector, so I don't take anything apart, but it's very helpful to understand what the hell is going on behind those pesky switch plate covers. Definitely been flummoxed by this situation in the past!

Great explanation, I had never heard of this.

Great explanation!

Awesome video, I believe I watched my mentor blast his way through trying to fix one of these, Awesome work 👍

Super clear explanation.

I found this chicago 3 way in a 1920s farm house here in Denver. the home owner changed the switches but got the wires mixed up. I figured it out and got it working so my recommendation. if you change the switches pay attention to where the terminals are on the old switches and on the new one(especially the common).

I thankfully don't do a lot of resi work and in 30+ years have never run into this.. Was still done once romex style cable was used or was this primarily in knob in tube wiring? Thanks for the vid. Wicked good explanation!

Thank You. Good info!😊

Thought i was crazy . Years ago had one of these . Really thought i was crazy . Thx for the video

Young electrician raised on standard and dead-end methods. This just blew my mind. The ah-hah moment halfway through the video when I realized the light's polarity was going to be switched made me realize this is hick-ingenuity.

Excellent video!

Electrical Contractor in Maine since 1998 and have been in the trades for over 40 years and I have seen some things....but this Chicago 3 way is new to me. Great presentation sir, thank you. I find it shocking (pun intended) that was ever Code....with no ground available it's down right reckless to have both fixture wires hot at the same time. Treat every wire like a hot when the power is on is what I tell others.....I have lost count of the energized grounds and even metal casings I have found energized over the years.

I’m gobsmacked how crazy that is. I’ve never known anything but a true 3 way with 3/w ground Romex.

been an electrician for 25 years and this is the first ive heard of this type of 3 way. very interesting but wow that could be dangerous

I figured out there was probably a way to make a 3 way with only 2 conductors but seing it explained so clearly is quite cool. Thank you.

Control by switching the neutral is one sure way to get somebody hurt. Never knew this was allowed and even worse that it still exists. Thanks for excellent explanation.

Very cool. Here in Oklahoma, many residential electricians and service electricians know of the Arkansas 3-way and the California 3-way, but this is the first I've heard of this one. - Arkansas: in old houses where the circuit hot was brought first to the fixture box in the middle of the ceiling, a 14:2 Romex cable would be taken to the first 3W switch where only the black was used for power to the switch. (The white was not used). Then between switches, again 14:2 was strung for travelers. Then a third 14:2 was run from the second 3W switch back to the light fixture as a switchleg. (Again, the white was unused.) - California: In stairwells where the circuit is closer to the upper switch and also to the fixture than any of these three are to the bottom switch, a 12:2 Romex is run to the upper switch for hot and neutral. Then a 12:3 is run from the upper switch down two the lower switch: white phased as constant hot, red and black for travelers. In the upper switch box, the circuit hot is NOT landed on the common screw of the upper switch; it is instead spliced to the hot-phased white inside the upper switch box. Finally, a 12:2 is run from the upper switch box to the fixture: white being neutral, and black being the switchleg tied the common screw.

Seems like Chicago was always intent on burning itself to the ground. Dang! In 50 yrs of doing electrical work I thought I had seen it all. I've even worked on a number of old homes with knob n tube wiring and never come across this one. In fact, never heard of it, but thanks for the info.

I would like to learn NFPA 70 requirements for Swimming Pool lights. Really enjoy your videos!!

I like it, good thinking a long time ago. Good jobbexplaining

Wow! I wonder who came up with that arrangement? 😂😂 I'm glad I don't do work in Chicago! I have to say... in my 40+ years of doing electrical work (primarily industrial & commercial in SoCal/west coast & Texas) I've never come across this (fortunately, I guess!). Many years ago, I came across an old residence (that had been re-purposed to a Law office), in which I was contracted to do a lighting upgrade (the rooms all had old, 8' ballasted fluorescents)... until I discoverd that it still had knob-and-tube in the attic space - and it was still being utilized! Those conductors were all running VERY warm! That job ended up taking MUCH longer (and, costing substantially more) than what was originally quoted, as I had to [basically] rewire the entire place. Fortunately, the walls were old-school, real "bat & plaster" construction, so no fire-blocking to preventing the pulling-in of new/modern conductors. What a PIA! 😂

Damn great explanation.....THANKS!!

You're damn right that's lethal!!! Whose GENIUS idea was this?!

I subbed for an electrician in my early twenties and we’d come across things like this on old work. My background was in solid state electronics as a kid just for a hobby but I had a good understanding of electricity, electrical circuits, and semi conductors because of this. My boss had 15 years as an electrician and 8 years as his own private company. You’d be amazed at what a lot of electricians don’t know beyond basic simple circuit breakers/switch/outlet scenarios. I remember him looking at a three phase diagram like he was reading mandarin. And another time showing him how to wire a DPDT relay to reverse polarity on a projector screen. You’d swear he thought it was witchcraft lol. Point being, just because you have a degree or certification, doesn’t mean you know what you should know, and someone without doesn’t mean they don’t know….

Yes sir nice vid I live in a house in texas that we built in the late 50s early 60s One 3way in the house for living room, lit me up first time i attempted a ceiling fan replacement hahaha.. shut the main off after that😂 I re-wired a house from mid 40-50s same chic 3 way Like he said when it's old work is very difficult to identify a lot of the wiring especially since its all 2 wire and if it's really old.. the old cloth wrap cable that's all tied together w mech device and tar covering everything

It's crazy even if it does work. It's kinda like old pole lights on old buildings that were 220v and they just run one phase thru the contactor leaving one hot leg in the pole at all times.

I've never seen such a thing. Seems totally insane. The idea of a neutral being switched just can't fit in my brain. But, now you're making me wonder if my understanding of how it should work~~only switching hots~~is correct. I am definitely going to have to watch that next video.

Great video thank you

we even have them at up at canada, I have since encounter a few of these on my career.

Retired electrician. Good explanation on the Chicago 3-Way, but you get to blow up stuff with a Farmers 3-Way.....Ran into both types on a house I bought a few years ago as well as #18 speaker wire used for wiring from the switches to the can lights in the living room.

I see these in every house I’ve rehabbed. I’m from St. Louis, but any house that is a 2 wire with no ground (50s or earlier) was wired this way. I moved to Omaha and same thing here. It is totally confusing and I’ve been shocked a few times thinking the power was off when I turned the light switch off. I turn power off now.

Not exactly what I was expecting when I saw the title "Chicago 3-way". But, logically, it makes sense. Unconventional that that light fixture will always have at least 1 hot leg I mean, it works.

Wow my 1940s house had this. I didn't know it was called a Chicago 3 Way. It was so strange, two different lights in my house had this. I have since replaced the wiring but was confused how it worked. That is crazy how that worked!

I learned about this the hard way after attempting to install a new light in my father's garage, built in the 1970s. I was so angry to see such a dangerous installation just to save having to put in 30 feet of 3-conductor Romex. Then I remembered getting shocked as a kid (in the same house) changing a lightbulb that was turned off.

Great explanation. We called them hot switches.

Great vid. Great explanation. Viewers who don't understand any of this should not do any electrical work in their home!

I first encountered a setup like this in a house I had bought that was built in 1954, although it didn't use 3-way switches, it used similar methods. They had wired the outside porch light to be permanently on and use a sensor with the same wiring and circuit as the kitchen sink light and switch that controlled the kitchen light, outside light and "GFCI" plug in the same double wallplate. I wanted the light on the switch. I had everything off, yet got zapped by the neutral wires of all things. I also had the circuit breaker trip once I got everything hooked up correctly. I found out they had wired it like this where another switch on the opposite side of the kitchen, that didn't even control the light, put power through the neutral. I disconnected everything in all those circuits, used a wand toner to isolate each wire, and wired everything correctly. I still had a random hot neutral, but it wasn't in the circuit and I couldn't figure out where it went, so I capped it off, taped it off, labeled it, and stuck it back in the junction box. Poor wiring technique could have had bad consequences for someone who didn't identify it.

My step-mom's first husband thought he was really good at stuff and miswired 3-ways in the house I lived in. I should go back there now that I know how things work and finally fix it.

I've been an electrician for almost 40 years, I have never seen ANYTHING like this and I've worked in a lot of knob and tube homes(near Philadelphia region), glad I never came across this. It makes sense for functionality, but WOW! Lutron Caseta with Picos is an easy fix.

Very interesting. You will never find a circuit like that in the UK. That looks all so over complicated for no real advantage. Really interesting to see how different wiring is in other parts of the globe. Thanks for the lesson.

1:04 I love 3way and 4way switches!

At first I thought why would you do this then I remembered knob & tube used single conductors. Ah-haaaa!! Very cool video. I never knew this existed. I suppose when electricity was installed strictly for use as means to light a bulb, this might have been “ok” but yeah, I totally understand how dangerous it could be.

So does this mean you are going to make separate videos to cover the other 3-way methods you referenced in the video? This is definitely helpful but I am trying to put it into context and also trying to figure out how I can use a meter to figure out which is which in a case where the wiring is buried and it's not obvious.

Thank you. I think I have one of these in my house (built in 78). Fortunately, the wiring is somewhat accessible, so if I can confirm it, I can replace it with something sane.

Ah, thank you for finally explaining.

I encountered one of these after a friend was trying to replace a switch on a 3 way light circuit with a motion detector. He was baffled and asked me to have a look. I was also baffled and couldn't get it to work. Somehow the light kept managing to dimly light, receiving 80v. After us both being puzzled for a while we said screw it and he called an electrician. Now years later running across this at random, I'm almost sure this is how it was originally configured and likely why we didn't get it to work

I encountered one of these on an old house that put two bedrooms on the third floor attic. The extra confusing part was someone added a second light and put them in series. Needed two pretty close light bulbs to get dim light out of both. I unscrewed the assumed dead bulb and the other went out. 😢.

Chicago Sparky here. It's standard practice, at least with the me and the firms I've worked with, to fix these when we come across them. Another advantage of everything being in EMT.

Thought it looked familiar. But I've always known it as the Carter System.

This was done everywhere when no one wanted to break open plaster and run new wires .Not to code but works electrically !

Here im Germany we call this a "Hamburger Wechselschsltung" (Has nothing to do with burgers, the Name comes from the City Hamburg). And of course it is also forbidden here since it is very dangerous, but until now I luckily didn't ever even encounter one in the wild.