Now what do I do. I change my kitchen and bar fixtures no problem. I'm having trouble with the wiring in my bathroom. I went to replace the ceiling fixture in my bathroom and there are three thick wires each with one black one white and a ground wire. One of the wires is always on not controlled by the switch and when I have hooked the other ones up I get nothing. When I took down the old fixture I should have paid more attention but I figured means the kitchen and bar light went so smooth I would just hook this light up like the other ones. There has never been a vanity light or a fan just a single light fixture in the bathroom so I assume these wires would be if you wanted to install those later. I just want to put a ceiling light fixture in there. Thanks Jessica

Hi Jessica,

The three thick wires are called cables. One cable, the one that is always on, is bringing the power to the ceiling box. One of the other cables is carrying the power to another fixture or outlet and the remaining cable is for taking the power to the switch and back to the light (when switch is turned on).

You know which cable is bringing the power to the ceiling box. Your problem is to determined which of the other two cables takes the power to the switch, and which takes the power to the other fixture or outlet.

Find the other fixture or outlet that is not working. That fixture or outlet may be in that bath or it may be in another room.

With the switch in the off position, repeat make sure that the switch is turned off, temporarily connect the black wire of the cable bring the power to the box to the black wire of one of the other cables. Connect the white to the white.

Verify that the switch is still off and turn the circuit breaker on. Check the fixture that was not working and see if it is now working. If it is now working you have correctly reconnected that cable. If the fixture does not work, disconnect that cable and temporarily connect the other cable and repeat the check.

After you have identified which cable goes where, put a piece of black tape on the white wire of the cable that goes to the switch.

Connect the black wire of the hot cable, the black wire of the cable going to the other fixture, and the white wire of the cable going to the switch (the one with the black tape). Connect the white wire of the hot cable, the white wire of the cable going to the other fixture and the white wire of the light you are installing. Connect the black wire of the switch cable to the black wire of the light you are installing.

Hi Jessica,

A word of caution please. It is very important that you know the destination of the third wire.

I'm concerned that it may go to an electrical outlet in the bathroom. If it does, then that is a code violation. You cannot mix lighting and receptacles on the same circuit.

Don please back up your claim that:

"You cannot mix lighting and receptacles on the same circuit".

Since when? Your statement will be confusing to others that read this.

Did you know that general purpose lighting circuits typically connect to lighting outlets AND receptacles?

Did you also know that a dedicated circuit for one bathroom receptacle is allowed to have that bathroom light and the exhaust fan on the same circuit?

Only the small appliance circuits required in kitchens, dining rooms, etc, do not allow lighting outlets.

The circuit being discussed I bet is a general purpose lighting circuit.

TK,

Yes I know that. However bathrooms are different according to the 2008 code.

From past work, a separate line in for the lighting was to protect against a circuit failure because of high wattage and leaving the bathroom dark. I 'm sure if you used a GFCI outlet in the bathroom and set it after the lighting connection you can achieve the same thing.

Anyway, here are the cites, please let me know if I misinterpreted any of the codes.

210.8(A)(1); 210.11 (C)(3) & exception; 210.23(A)(1) exception &210.52 (D); 220.14 (J) ?