Electrical puzzle

the diagrams at

if I understand what you are trying to do, you may need to wire the H1G1 set as "Basic", and the H2G2 set as "Variation #3", involving a total of 6 wires between house and garage. Note that Var 3 really does not have a "neutral" between the house and garage !!

Assuming you have 2 two gang boxes at each location and two 3way switches at each location. You have to have 2 wires at either location going to each light. you need a feed brought into one of the switch locations, and you'll need 3 wires going from each switch to it's corresponding switch location

Think of it this way: 2 lights in hallway with 3/w at each entrance. Same connections you are searching for.

Of course you're one wire short. A 3-way switch needs 3 wires. Two 3-way switches requires 6 wires. "Sharing the neutral" doesn't have anything at all to do with this. That's a completely different matter -- suggest you Google on "shared neutral circuit" or "Edison circuit" for an explanation.

Replace the 14/2 cable with a 14/3.

Assuming your existing wiring is

powerH->H1->H2->lightH (basic 3-way switch) powerG->G1->G2->lightG (also basic 3-way switch)

Between H1 and H2 you would find 3 to 4 wires (ground, neutral, and two traveller wires). Ground wire doesn't have to come from H1 to H2; it could come from anywhere, I believe.

Between G1 and G2 you would find the same.

In theory, you can make it work with 4 wires between the house and the garage (two travelers from house to garage, and two travelers from garage to house). If you do this you'd end up with:

powerH->H1->G2->lightG powerG->G1->H2->lightH

The only wirings you change is between H1->H2, and G1->G2.

Doing this would mean combining hot from one source with neutral from another source. This is very unusual way to wire stuff. If one of the sources has a GFCI or AFCI this kind of wiring would cause problem. It may also be against electrical code. And even if it isn't, I wouldn't do it if I were you.

To avoid mixing hot and neutral, you need 3 wires between H1 G2, and G1 H2. So, the best solution is to replace the 14/2 in the conduit with a 14/3 so you can have 6 wires.

If you don't want to change the conduit, you can choose to have one of the lights (the garage or the house) works as a 3-way, and then wire the other light as a normal one-switch light.

Nice explanation.

If wiring it with cables you need a 3-wire for each light. If you need power at the garage you need another 2 wire.

If wiring with conduit and wires you need 6 wires (not including ground). If you need power you can still use 6 wires and connect one of the 3-ways as a "California 3-way".

If you used a 3-way at each end to control both lights at the same time (2 switches total) you could also use a "California 3-way" (also gives power at the garage). Requires 4 wires in conduit. Since a couple codes ago this requires a 4 wire cable.

You can use what you have if one of the 3-ways uses an X10 control.

(You don't detail your wiring method. Cables in buried conduit have to be UF (not Romex).)

-- bud--

Aaron How do those two cables reach the garage? Is the garage attached or detached? What kind of cable did you use? What Country, State / Province are you located in? Answer those questions and we can give you much better answers.

-- Tom Horne