Wiring in my garage, question....

[JPG]

A typical residential dwelling will use romex cable. The wire colors will be White(neutral), Green(ground), and black(hot maybe), and red(hot maybe).

3 conductor(with ground) will be white/black.red/bare.

The reason for the 'maybes' above, is that switch/lamp fixture can be switched, and therefore not 'always' hot. Ground and neutral wiring is 'always' directly connected to ground and neutral(NEVER switched[in the structure wiring]).

There are occasions where two and three conductor cable will be used with the white wire something other than neutral. In that case, the white wire must(should) be marked to distinguish it from an 'identified neutral conductor(white wire).

Now when conduit is used, fergit all the above except for the green.barew and white conductors.

Yellow and blue conductors are commonly used(as well as other colors like orange, brown...), but 'supply' conductor(those directly connected to the 'panel' should be white/green/black/red only.

Gets really fun when a 4 gang switch box contains a dozen or so wires, all the same color and none of them go directly to the panel!:D

As for Ed's pre-wired for door opener, I guess the lamp socket was used by the opener to provide interior lighting. More recent openers are self contained as described above, and the light is internal, and the power source is a line cord.

[reible]

Took a little time this afternoon to think about what I'm seeing.

Things are starting to fall into place. First the switch is a two way switch, why I didn't pick up on that I don't know. The second switch is on the opposite side of the garage need the big door. I never use it and I forgot it was even there.

With that in mind I now know where the yellow wire comes from. It has to be from the other switch. (Haven't checked the box yet).

Starting at the switch box it then makes since that the red and white lead coming from the one conduit could from the panel (or feed more of the circuit). The red wire attaches to the switch then exits out the other conduit. The two blue wires are on there way to the other switch via the ceiling box.

Now at the ceiling box the blue wires come from the switch and go to the other switch. This accounts for the 4 blue wires. These remain as only part of the two way wiring. The yellow will be going to the second switch only.

The ceiling box has a red and white coming in one conduit which could either be from the panel or leaving for another destination. The other conduit has a red white and two blue wires that I believe come from the first switch. I see no way of identifying those red white wired as to which goes to the panel. The garage has all walls and ceiling covered so no visual aids.

Well I guess I could open the red wire and see what connections go dark but that might be really needed as it would seem that picking a red wire and a white wire should give me an outlet.

It does appear that no special circuit was add for a door opener. I also believe code prohibits a hidden box (covered with drywall) so I don't think I will look for one.

Is any of this make since now?

Ed

[Ed in Tampa]

My guess the red white and black wire is for the 2 way switch. That is usually the color used. My second guess is the blue wires might be for a garage door opener circuit.
Again go buy a voltage detector and you don't have to disconnect or anything just see who is carrying voltage all the time and who is switched. Easy as pie

[JPG]

Let us call the switch(es) a 3 way switch. I assume the two blue wires are attached to different terminals.

Then it makes much sense.

Two 3 way switches, controlling the lamp socket and a feed to something else.

Red and white in and out.

blue between 3 way switches

yellow from second 3 way switch to the lamp.

red hot feeds the first 3 way switch

white also feeds the lamp neutral

minimalist suggestion still stands, except keep the lamp connected!;)