How to Rewire a Light Switch to Control a Ceiling Fan (Power Source Enters at the Outlet)
If you have a light switch that controls an outlet – and the power source enters at the outlet – here’s how to rewire the light switch so that the outlet is always on and the light switch can instead control a ceiling fan/overhead light.
In my last post I described how to rewire a light switch that controls an outlet to instead control a ceiling fan/overhead light, when power enters at the light switch (link to that post here). In this post I explain how to handle the case when the power source enters at the outlet.
Review of the existing wiring: the light switch controls an outlet (power source enters at the outlet)
Before I explain how to rewire this setup, I think it’s important to summarize how the existing electrical wiring works. That way you’ll understand what needs to change, and most importantly why it needs to change!
I’ve created the following diagram for switch-controlled outlet wiring:
Let’s review the important electrical connections (indicated by blue numbers in the diagram):
- Black wire from the power source (in the outlet electrical box) is connected to the white wire running to the light switch (in the outlet electrical box) with a wire nut.
- If the black wire from the power source were connected directly to the outlet, then the outlet would always be on. Since this outlet is controlled by a light switch, current first needs to go to the light switch. We do that using the white wire that runs to the light switch.
- White wire from the outlet (in the light switch electrical box) is connected to the light switch.
- This provides current to the light switch (remember the other end of this white wire – in the outlet electrical box – is connected to the black wire from the power source).
- Per convention this white wire (in the light switch electrical box) is often wrapped in black electrical tape to indicate that it is really live/hot.
- Black wire from the outlet (in the light switch electrical box) is connected to the light switch.
- This provides a return path for current to the outlet whenever the outlet is turned on by the light switch.
- Both ground wires in the outlet electrical box (one from the power source and the other from the outlet) are wire nutted together and attached to the outlet green/ground screw with a pigtail.
The new wiring: the outlet is independent of the light switch, and the light switch controls a ceiling fan/overhead light (power source enters at the outlet)
The following diagram explains how to take this existing setup and rewire it so that the light switch can now control a ceiling fan/overhead light:
- Black wire from the power source (in the outlet electrical box) is connected to the outlet.
- This provides current to the circuit, and since it is directly attached to the outlet then the outlet will always be on – the outlet is now independent of the light switch.
- White wire from the power source (in the outlet electrical box) is connected to the outlet.
- This wire connection hasn’t changed, but I want to emphasize that current to the outlet in Step 1 has a return path and this path is independent of the light switch.
- Black wire from the outlet (in the outlet electrical box) is connected to the outlet.
- This wire connection hasn’t changed, but its function has changed. This wire is providing current to the light switch.
- Black wire to light switch (in the light switch electrical box) is connected to the light switch.
- This wire finishes bringing current to the light switch.
- Black wire from the ceiling fan (new Romex cable that’s been run into the light switch electrical box) is connected to the light switch.
- This provides current to the ceiling fan, and since the ceiling fan is now connected to the light switch then current to the ceiling fan is now controlled by the light switch.
- The two white wires in the light switch electrical box (one from the ceiling fan and the other from the outlet) are connected together with a wire nut.
- Connecting these two white wires together provides a return path for current from the ceiling fan whenever the light switch is turned on.
- The white wire from the light switch (in the outlet electrical box) is connected to the outlet.
- This completes the return path for current from the ceiling fan.
- Both ground wires in the light switch electrical box (one from the ceiling fan and the other from the light switch) are wire nutted together and attached to the light switch green/ground screw with a pigtail.
Congratulations! You’ve successfully rewired a light switch that once controlled an outlet to instead control a new ceiling fan/overhead light!
Note
Only perform electrical work if you are comfortable and qualified to do so, otherwise consult an electrician. And always turn off power to the light switch and outlet at the main electrical panel before doing any rewiring!
Did this guide help you rewire a light switch that controls an outlet to instead control a ceiling fan? Have any other electrical wiring questions? Let me know in the comments below!
Explore more home improvement projects at ProjectsByPeter.com/Home-Improvement
Post content and images © 2022 ProjectsByPeter.com – All rights reserved.
Hi Peter, I have a switch outlet connected to a half-hot receptical outlet. Both have two lines coming in. One line is 14-2, the other line is 14-3. How do I determine if either of these 14-2 lines come from the power source. These two outlets are on separate breakers from the rest of the outlets in the room however, they are on the same breaker as other outlets in the house. My intent is to install a new fan/light combo using the switch outlet however, I will be replacing the existing single switch with a dual slide fan/light switch.
Hi Kathleen,
You’ll have to try to backtrack the Romex wires coming into the switch outlet and receptacle outlet as best you can to determine where electrical power is coming from.
For me, in the case where the electrical power entered at the switch outlet, there was one Romex cable coming from the direction of the attic (above the room I was in) straight down into the switch outlet’s electrical box. I was able to confirm this by wiggling/shaking this Romex cable a bit from the attic and having a partner verify movement in the switch outlet’s electrical box. I followed this Romex wire in the attic where it went into a very large junction box that contained other Romex wires branching out of it. So it was clear that electrical power was brought up to the attic into this large junction box, then split off from there. So I knew, in this case, electrical power was coming into the switch outlet.
In the case where the electrical power came from the receptacle outlet, there was only one Romex cable going into the switch outlet that controlled the receptacle outlet. So the only option here was that power was coming from the receptacle outlet and going to the switch outlet.
Definitely takes some detective work. If you take off wall plates and unscrew the receptacles a bit, a little wiggling/shaking of the Romex cables should help you determine where they are connected to, and hopefully you don’t have to backtrack things too much!
All the best,
Peter