How to wire 3 way switch - Lutron Electronics MAW603RHWH Maestro 3Way Duo Dimmer

All 3 switches should be grounded, plus one box should have a ground wire to the box ground screw, all ground wires into the 3 gang should be connected together, run a 4th to the metal box and one to each switch ground.

Copy following link for 3-way switch wiring diagram:
http://waterheatertimer.org/How-to-wire-switches.html#3-way

Add a comment and say if you are adding a 3-way switch to existing single-pole switch.
You need 3 wires running to new 3-way switch.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

You have 3 cables entering the box.
Each cable has black and white and ground wire.
You have a single pole switch.
The switch has 2 brass-colored screws and 1 green-colored screw.

1) One thing is certain: all the ground wires connect together and then connect to green screw on switch.

2) After that, we are guessing without more information.
Add a comment.

3) What does the switch control?

4) If the switch controls a hallway light, and there is another switch for the same light: then you have wrong switch. You need 3-way switch. Buy 3-way switch and re-post question at fixya.

5) If switch controls a bath fan-light combo, repost question at fixya.

6) If the switch controls a regular light, and no other switch is involved: then the following information might work. Or you need to do testing and re-post another question at fixya.

-White wires probably connect together and are covered with a wire nut.

-Then two black wires connect to one brass screw and 1 black wire connects to other brass screw.

-But which black wire?

-Only one of the black wires has power from circuit breaker. That is hot wire.
-Hot wire connects to 1st brass screw on switch. Either screw.

-And then connect one of the other black wires to 2nd brass screw. Turn on power and see if light turns on.
-Try other black wire same way.
-The black wire(s) that turn on lights on should be left connected to 2nd brass screw.
-If one black wire did not turn on lights, then that wire probably connects to 1st brass screw along with hot wire.

You posted under ST01C and are wiring timer to replace 3-way switch.
Open following link for specific illustrations:
http://waterheatertimer.org/ST01C-program.html#ST01C
http://waterheatertimer.org/pdf/ST01C-explanation.rtf

1) The timer replaces one of the 3-way switches. The other 3-way switch remains, but must be rewired.
2) The timer must replace the 3-way switch that receives power from breaker box. It cannot replace the other 3-way switch. This is because the timer Black wire must always receive power.
3) The timer blue wire must connect to Load (light)
4) The ST01C red wire is only used when wiring for 3-way.
5) When the red wire and blue wire are connected together, they reverse the timer program. When timer red and blue are disconnected, the timer resumes programming. Connecting and disconnecting the red and blue wires is how the timer mimics 3-way operation.
6) The remaining 3-way switch must be wired so it will connect and disconnect the red and blue timer wires. So the remaining 3-way switch has to be rewired to meet specific timer wiring.

ST01C timer replaces one 3-way switch and the other 3-way switch remains.
The ST01C timer does not work exactly like a 3-way switch.
When the timer blue and red wires are connected together, they reverse whatever program is in effect.
When the timer is wired for single-pole, the red wire is capped off. When timer is wired for 3-way, the red wire is used to reverse the timer, thus causing the 3-way effect.
So if timer is ON, and red and blue wires are put together, the timer turns OFF.
That's why the remaining 3-way switch has to be rewired.
The remaining 3-way switch is rewired so it will connect and disconnect the red and blue wires, causing the timer to reverse program each time, and creating 3-way effect.
Other requirements of ST01C is that the black wire must connect to Hot wire, and the blue wire must always connect to Load. This means that you have to correctly pick which 3-way switch to replace, where the hot wire from breaker arrives.
Open following link for wiring diagram showing how to wire for 3-way:
http://waterheatertimer.org/ST01C-program.html#ST01C
All 3-way timers require rewiring second 3-way switch to create 3-way effect.

Wiring is not fully described: Location of hot wire and neutral wire from breaker box are unknown.
If Hot wire arrives in ceiling box first, the switch box will not have white neutral wires that are twisted together and covered with wire nut. Neutrals will be in ceiling box.

What is known: You are replacing single pole switch attached to one 14-2 wire going to light.
You are replacing light with a fan-light and replacing switch with a 3-pole TM8111 switch.
You have replaced 14-2 wire with 12-3 wire.

TM8111 wiring shows following link:
http://waterheatertimer.org/images/TM8111-switch-wiring-500.jpg
Fan pull-chain wiring shows following link:
http://waterheatertimer.org/images/Fan-motor-1-344.jpg
Assume neutrals in ceiling box.
Assume Hot wire in ceiling box: Connect 12-3 black wire to black Hot wire. Connect 12-3 white wire to black wire on light. Connect 12-3 red to red wire on fan.
White neutral from fan and white neutral form light connect to other white neutral wires and covered with wire nut.
Wiring at switch:
Black Hot wire from ceiling box connects to A COM terminal.
White wire to ceiling light connects to A SP2
Red wire to fan connects to A SP1

Decora 3-way and 4-way switches do not wire differently than toggle-type switches.
Instructions below are tedious but will accurately guide you to solution.

Let's break down the problem starting with 3-ways.

1) Start with 3-way switches:
Old 3-way switch has 2 brass screws and 1 dark screw
New decora has same color screws.
Wire that went to dark screw on old device must attach to dark screw on decora device.
Other two wires can attach to either brass screw.
Wires that attach to brass screws are travelers ... these wires travel to the 4-way switch.
So there are 2 traveler wires at each 3-way switch.

2) Let's test if 3-way switches are wired correctly by taking 4-way switch out of equation.
We will resolve problem with 4-way switch after 3-ways are correct.

There are 4 wires at the 4-way switch.
These are the 2 traveler wires that arrive from each 3-way switch.

At the 4-way switch, 2 wires arrive in one cable, and 2 wires arrive from another cable.
To say it differently, there are 2 wires from cable1 and 2 wires from cable2.
Connect 1 wire from cable1 to 1 wire from cable2 with a wire nut
Now connect the 2nd wire from cable1 to 2nd wire from cable2 with another wire nut.
So now the traveler wires are connected, and the 4 way switch is out of equation.
Turn on power, and click 3-way switches to see if both switches turn lights on-off in all positions.

Do your 3-way switches work correctly?

3) If 3-ways are not correct, then you have wrong wire connected to dark screw.
First thing to check is if you can identify traveler wire colors by looking at wires at 4-way switch.
Remember, traveler wires at 4-way switch go back to 3-way switch and connect to brass screws on 3-way switch.

4) If you cannot tell traveler wires by looking at 4-way switch, then you can try different combinations until both 3-way switches work.
Or you can test: disconnect wires from one of the 3-way switches. Separate 3 wires for testing. Move other 3-way switch to down position. Turn on power. Test each wire to bare ground wire. Mark wire that lights up. Now move other 3-way to up position. Test each wire to bare ground wire. If same wire lights up each test, then that wire goes to dark screw. If different wire lights up, then mark that wire. The two marked wires are travelers, and they connect to brass screws. Other wire connects to dark screw. Repeat identical test for other 3-way switch.

At this point your 3-way switches will work, if light bubs are not burned out.

5) Last step, the 4 way switch.
Remember from step above, that 2 wires arrive in cable1: These 2 wires connect on one side of 4-way switch. The other 2 wires that arrive in cable2 connect of other side of 4-way switch.

Add a comment if you need more help.

Yes, you can. Since you have power at the one 3-way switch already. Use two of the three wires to go DIRECTLY through to the other 3-way switch. Make sure NOT to connect these wires to anything other than to the 3-way switch. Now, you have power at the one 3-way switch - and the two wires (called travelers, jockeys, etc.) going directly over to the other 3-way switch. You already have your neutral at your lights, so that's taken care of. Now, wire each of the four lights together - and take your remaining wire down (connect it) to the (powerless) 3-way switch where you just brought the two travelers/jockey wires to. Land this on the colored/odd screw on the 3-way switch. Now, the 3-wire cable that came from the 3-way switch that had power to it already...has a remaining wire that you will cap. You used the two wires to go directly over to the other 3-way switch - and now, that third wire can just be capped (or taped off). So basically, you have power at one 3-way switch. You have two wires going directly to the other 3-way switch. And from this switch, you have a wire going to your lights. The neutrals are connected together between the four lights (which I'm presuming have already been connected back to a neutral source, or your electrical panel). I hope this helps. If not, please contact me again. Good Luck, and I wish you well.  - Jim

You have to run the 3rd wire all the way to the switch, whether it hits any lights or not, I have seen electricians pull a single wire in to the box with the 14/2 and that would be the jumper. This will work on any lights, and the lights only need the 2 wires, It is just the switch that needs the 3 wires. Good luck.

before u start make sure power is off before working with electrical lines ---start with the 12/2 coming into box black [power] white [ground-neutral] and u will have 3 separate lines for the lights so u will have 4 lines total coming in the box== with the 3 light lines take the white and strip back the plastic and connect [wire nut] all 3 to the 12/2 white line --now take the 12/2 black line and connect it to the first switch gold color screw- bottom screw -now take some wire about 2-3 inch strip both ends and connect from the 12/2 black wire connection on the switch and connect to the gold /bottom of switch 2 than do the same for switch 3 connecting the wire from switch 2 so u will have power feeding all 3 switches-- now connect the black lines for the lights to the other side of each switch and ur done