In article .com,
wrote:
I have a bit of a dillema with my bathroom lighting. I am trying to
install a new light above the mirror but i just can't seem to get it to
hook up properly. The existing light worked and I was positive I saw
what was already hooked up and did the same with the new light. I have
black to black and white to white, but still nothing works. The concern
that I have, and which is more than likely the case, is that I am
attaching the wrong wires. There are three sets of black and white
wires comig out from the back of the lighting panel. If you picture the
octagonal box facing you there are to sets of wires on the far left
(which is closest to the wall with the light switch) one above the
other, and then the last set of black and white wires are located down
towards the bottom right corner of the oct. box. THe white wire from
the bottom right one is left open whereas the other white wires have
been merretted together. My problem lies with the black wires. Since
there are three of them exposed I have tried connecting the black wire
from the new light to each one of them and still no luck with power. I
hope I have explained everything ok, if not I will try to give as much
clarification as possible if anyone is willing to help.

Here is my best guess:

The 3 b/w pairs a
1) Supply from the breaker.
2) The switch.
3) feed to some other light or fan.

Seperate all wires. See if one pair has 110vac on it. Thats #1.

If the other 2 pairs have zero voltage between then and to ground, then
use an ohmmeter (or continuity tester). If one goes from zero ohms to
infinite ohms with flipping the switch, Thats #2.

If the third pair has continuity independant of the switch and is some
value greater than zero ohms, thats (probably) #3.

Turn the breaker off. Connect the #1 & #3 pairs together, black to
black and white to white. Turn the breaker on. Is another light or a
fan now on? If yes, your rolling. Turn the breaker off again.

Disconnect the temporary connection between #1 & #3. Connect #3 to the
light fixture matching colors.

Connect the white wire of #1 to the white of the fixture & #3.

Connect the black wire of #1 to the black of #2.

Connect the white of #2 to the black of the fixture & #3.

Check the wireing, turn switch off. Turn breaker on. If my guesses are
correct and you did it right all should work.

If it turns out that you did NOT want whatever is on #3 to be controlled
by the switch but on always (perhaps it has its own switch), move the
black & white of #3 from the b/w of the fixture to the b/w of #1.

Put everything back together and clean up.

NOTE: If you are not comfortable doing the tests and connections I have
described, CALL AN ELECTRICIAN.

--
Rich Greenberg Marietta, GA, USA richgr atsign panix.com + 1 770 321 6507
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
Canines:Val, Red & Shasta (RIP),Red, husky Owner:Chinook-L
Atlanta Siberian Husky Rescue. www.panix.com/~richgr/ Asst Owner:Sibernet-L