Changing light fixtures- why do I have an extra wire?

I'm switching fixtures in my dining room and bedroom. The dining room has white-white, black-black and silver-ground. The bedroom has white-white, black-red, silver-ground and an extra black wire from the ceiling. What is the black wire for? Do I install the other light fixture and leave the black hanging? Or leave the red hanging? Or is this over my head?



Please only answer if you KNOW. I'll take your word for it and get myself killed :). Thanks.
Changing light fixtures- why do I have an extra wire?
The answer is that either of the previous answers could be correct.

The red indicates that it is the runner from a 3 way switch, in which case look around and see if you have an extra wall switch somewhere that is not apparently doing anything (that would indicate it was once controlled by 2 switches). If the answer is no then it could have controlled a ceiling fan (if only one Wall switch) the fan could have been controlled by the wall switch and the light by a pull chain (or vise versa).

The answer to your question is:

(go to last paragraph before doing anything)..quick and dirty solution.

Turn off the breaker (be carefull use rubber shoes and use one hand) and for peets sake don't hold on to a radiator or anything that is grounded. Detach wires in ceiling from old fixture if not done yet..(There could actually be 2 circuits in either of the rooms). If you are really paranoid turn off main breaker (have someone hold a flashlight). Do not separate wires from wire nuts leave then because you must have a switch leg in there.... Turn circuit breaker back on. Get a volt meter or ($1.29 120v lighted tester)....Touch tester to a white and then a black and then the red. Tester should light up when you get a complete circuit..either the black, red or both. If no light or voltage indicated flip wall switch and try again......Use the lead that indicates voltage when switch is on and none when it's off...that one goes to the black on your new fixture...white just goes to white on new fixture.

Relax it's only 120 volts AC (easy to shake free from..just don't let it cross your heart that's why we work with one hand often on live circuits)..

If white to others does not work..try black to red....in case they hired a Good Old Boy from Mex-e-co!

I've seen some very stange wiring in my day.....In the unlikly event both black-red are live and are conctrolled by switch just put an orang wirnut on one and leave it in box..vynl tape is OK too.



To really make you life easy, if the previous fixture worked just wire new fixture exactly like old on was...and forget testers. Too be safe shut off main..who knows what they did!



Good Luck

Master Quark
Changing light fixtures- why do I have an extra wire?
this is generally the sign of a 3 way circuit ( one controlled by 2 switches) but could be a single circuit that some one just used left over 3 way wire for,,,be careful get a voltage tester
The black/red wire is used for the fan and the extra black wire is used for the light. You should have two switches on the wall - one for the fan and one for the light. Pete
Master Quark is what's up. I would have given you some half *** answer. Same principle, just really brief! They must call him Master for something.