Hi-
I want to replace my bathroom exhaust fan switch with a "Dewstop" moisture sensing exhaust fan switch and need some help.

The instructions say to match the neutral, power, ground and fan wires from the existing fan switch. I dont have these four wires coming from my exhaust fan switch. I only have a ground and two black wires, one to each pole.

Is there any way to hook up this fan/sensor switch with my existing wiring? This is a new home and the fan switch is mounted in a box with three other light switches.

Would appreciate your help. Thanks Tom
This is the link to the "Dewstop" website (which is no help)
DewStop: The Condensation Sensing Bathroom Exhaust Fan Switch

 

Unless you have conduit there should also be a couple of whites tied together. Pull the switch out and look behind it.

 

Hi Ray-
Thanks for getting back to me. I'll look again but I have pulled the switch out far enough to see a black wire going to each pole of the exhaust fan switch. If there are white wires then they are bundled up in the box or connected to one of the other 3 light switches.
I'll take a closer look and let you know. Thanks for the help.
Tom

 

Yes, that is where they would be.

 

I looked in there and it looks like there are some wires twisted and bundled together behind the 4 switches. It doesnt look like any of these bundled wires are tied to any of the switches. The switches only have 2 blacks and 1 ground going to them.

Is it possible to hook up the moisture sensor/exhaust switch that has a white, green, red and black wire to the existing wiring?

 

They shouldn't be. If they are white they are your neutrals.

Assuming the wires in the bundle are white proceed as below:

The neutral of the new switch (white) goes to the bundle of white neutrals in the back of the box. The ground goes to the bundle of bare ground wires in the box. The remaining two wires from the new switch connect to the black wires on the existing switch. If instead of two black wires it is red and black from the new switch stop and post back.

 

Thanks for the info Ray. I havnt had a chance to look at this yet but when I do, I'll let you know how it goes.

 

"If instead of two black wires it is red and black from the new switch stop and post back. "

Sorry it took so long to get back to you on this but the switch priority slid backwards when the wife eased up on the nagging;-) Well the switch priority has moved up again......

Yes there is a black and red wire from the new switch. Black is labeled "power" and red is labeled "fan." So I'm all checked out on the neutral and ground wires but need a home for the red and black wires. The existing switch has two black wires and a ground wire.
Thanks for the help,
Tom

 

Ground wire is easy. It goes with the other ground wires.

Using a multimeter or test light you need to check each of the blacks on the existing switch to neutral to see which is hot. That goes to the black of the new switch. The other goes to red.

 

Thanks Ray. I'll try it and let you know if I have a problem.