Bath fan/light switch

Question

Residential, bathroom, switching a fan/light switch to a fan/light/humidity switch.

I have 3 Romex coming into the box and each have a white, black, and ground. From left to right 1, 2, 3. One switch turns on the light and fan together and I¡¯m okay with that. White on 1, 2, 3, and the switch were wire nut together. 2 black went to the switch 1 and 3 black were wire nut together.

The new switch has a humidity sensor on it and should turn the light/fan on when you take a shower and shut off when the humidity is gone. It would be nice to separate the light from the fan, but I can¡¯t seem to do it from the receptacle box. There are 4 wires on the new switch, blue ¨C light, red ¨C fan, black ¨C hot, white ¨C neutral. I wired all the whites together Black 1, 2 and blue on the switch are wire nut together Black 3 is connected to the switch. Red I just capped, it doesn¡¯t seem to do anything. I¡¯m thinking it¡¯s because at the fixture the fan and light are wired together. All the grounds are connected together.

Did I wire this correctly? Thank you, Randy

Answer

Randy You are correct the wires that up to fan/light are probably on one switch leg wire. Does this Fan/light have a heater or a exhaust? When you say fan thats usually used with a Heat/vent/light type of unit.What you have is either a hot incoming and a hot outgoing and the switch leg going to the unit.Or it may be like this 1 hot wire coming in and 2 switch legs going to the unit.

You Wrote "Black 1, 2 and blue on the switch are wire nut together"

Since the blue (Which is the light switch leg) has 2 blacks what does the other black go to in the unit??

You wrote (Black 3 is connected to the switch.) this is the incoming power.

You wrote (Red I just capped, it doesn¡¯t seem to do anything.)this red wires is the other switch leg for the fixture where you have 2 black wires going to the blue (Light) one cab be used for the light. Open the unit and see what wires are in there,I bet there are 2 black wires hooked up to the light and fan in this box. Thats where you need to separate the wires.