Hi all. I'm getting a lot of help in these forum and I really appreciate it.

My bathroom currently has a fan and light combo mounted in the center of the ceiling, and there is a double gang switch that operates each function independently. There is no vanity light. I would like to install a vanity light, and (if needed) disconnect the light in the ceiling, but keep the exhaust fan.

If my thinking is correct, I will pull out the light/fan combo, determine which wiring operates the light, disconnect the wiring, pull out the double gang switch, pull on the wiring on the side that operates the light, pulling it through the ceiling and down the wall, cut a hole above the vanity mirror, fish the wires through, and then?

 

The cables will be secured in the walls and ceiling. You will not be able to pull them out.

You might be able to fish cable into the switch box from above if you have access.

 

How can I gain access? I misunderstood the terminology so I edited this post.

 

That would be from the attic above the space, if you have one. If no attic or if you have another finished floor above the space, you'll have to remove some drywall. You likely have a 3-wire cable feeding the fan/light so disconnecting the light really accomplishes nothing. I think I would just run a new cable from the switch box to the new light location and switch it from the ceiling light switch, along with the ceiling light.

 

Ah, ok, I had understood it correctly the first time. I do have an attic, where the fan is actually erroneously venting into. When that was found during my buyer's inspection (along with some mold), I decided to not use the fan until I could fix it.

Let me make sure I have the terminology straight. I've been on youtube watching videos about this and I've seen all kinds of crazy things. The switch box is on the wall, when you walk in, you flip the switch upwards and the light turns on. If that is correct, how am I accessing it from the attic? I was assuming I would cut a hole in the wall and fish it through to the switch box. Am I making it more simplistic than it is?

I would just go up in the attic and check things out, but I don't have a ladder and there is no pull-down. If I have to go up there to do this, I will find a way, however.

 

The wiring for the fan and light both appear at the switches. You can certainly run your new vanity light cable directly into the switchbox. Usually..... it's easier to work from the attic as you wouldn't have to open any sheetrock as you could connect your vanity light right at the fan/light unit.


Your wall is not just "open". You have studs every 16" so if the box for the vanity light is not in the same bay as the switch.... you don't have a clear shot.

 

Search for " house with wiring roughed in" to get an idea of how cables are run and what you would be dealing with when running the new wiring.

Once in the attic you should be able to find the top plate of the wall to drop the cable into.

 

And you would remove the existing switch box to have a "fishing hole" for the cable then replace it with an old work box. Boxes are usually nailed to the studs so you just cut the nails to remove the old box. A Sawzall is great for this but a hacksaw blade with a duct tape handle will work.

 

Sometime you can fish a string into an open knockout on the top of the box without removing it from the wall. Takes more time and practice but you don't need to unwire the box.

 

If you want an even easier option, find the top plate of the wall you would like the vanity fixture on, drill a hole, drop a 14/2 into it, and run the 14/2 to the fan. Tie it on to the hot powering the current light.

 

Just a heads up.

He also needs to determine if the existing two switches controlling the fan/light are switch legs (power coming from existing fan/light). If they are running a wire from the switch box to the new vanity light will not work. He would have to run the new wire from the existing fan/light to the vanity light and connect the wires accordingly in the existing fan/light box.

 

That's a good point, but I think it is highly unlikey this is the case. Most bath fans whether with light or not usually have a very small wiring compartment, so small that the power cable is almost always run to the switchbox.

 

Agree with you; however he should still check to see where power is coming from. He has not told us if there is an attic. In the case of my house the previous home owner put a junction box in the attic, ran a wire to the fan/light and then ran a switch leg to the switch box from the junction box. Also although it is wrong, I have seen fan/lights installed where the actual splicing was outside the box (power coming to that spot) and then a small romex length to the fan/light because there were too many wires to fit in there, and then the switch leg; some really goofy things I have seen.

 

I never say I have seen it all because I know something will also prove me wrong, but I have seen what you mentioned. Also have seen kitchen recessed lights wired inside the kitchen soffit.

 

I was called in on a job by a general Contractor that I worked for a few years ago. He was doing a demo of a wall in a church (the church was actually a rented store in a strip mall). Upon the demo of the wall one of the laborers happened upon a set of thick wires behind the wall they were taking down. I arrived and found that it was a splice in the wall (no box); the wires were live and it was a 480/277 3 phase, yikes!! :NO NO NO: Some people are so stupid.

 

I'm a "she", by the way.

How can I determine if they are switch legs?

In post #5 I say that I have an attic.

How will I be able to tell if I need to wire from the wall switch or the fan itself?

 

A switch loop is where power is taken to the fixture first and then the switch. The switch only has two wires connected to it, a black and a white and possibly a ground. The white is the hot to the switch.

 

^^^ What Mr.Awesome said.

Your existing fan/light has to have a neutral to work, which it currently is, and you can turn it on and off so you have a switched hot there too.
What will you need for your vanity light? A neutral and a switched hot. Plus you're looking at a single trip to your attic to run this cable and hook things up.