Electrical – How to independently control a light and fan, where only a single hot wire is used

The only product that I know of that will do what you want is the Lutron Maestro Light/Fan control. This product consists of a switch and canopy module. The switch will digitally talk to the canopy module over the single ungrounded wire and control lights/fan separately. The kits are one switch and one module but the switch can talk to 4 modules at once.

What you propose is indeed possible. How difficult it is, depends on what wiring is currently in place.

You should start by connecting all the bare/green grounding conductors in the switch box together, including a pigtail to both switches. Other than that, it sounds like the wiring in the switch box is good to go.

If you want to control the fan with a wall fan control, you can install that in place of the fan toggle switch.

In the ceiling box, you'll likely find the 12/3 cable from the switch box. If the existing fixture uses a remote module, you'll likely find that either the black or red wire from the 12/3 cable is simply capped off. You'll see the black/red, white and ground wire connect to the remote module. The remote module should connect to the fixture with a black, blue, white, and bare/green wire.

If you want to remove the remote module, you should disconnect it from all the wiring. Once disconnected, you can remove the module, or cap off all the wires and leave the module in place.

To control the fan using only the wall switches.

• Connect the white wire from the ceiling to the white wire from the fixture.
• Connect the bare/green wire from the ceiling to the bare/green wire from the fixture. If the box is metal, include a pigtail to the box.
• Connect the red wire from the ceiling to the blue wire from the fixture.
• Connect the black wire from the ceiling to the black wire from the fixture.

Now the switch connected to the red wire, should turn the light on/off. The switch connected to the black wire, should turn the fan on/off (and optionally adjust the speed).