I recently replaced the light and fan switches in the washroom with Leviton Occupancy Sensor switches (IPS02) which are intended for lights and motors. The wiring in the switch box is all black. There is a pigtail going from one switch to the other.

After rewiring, the occupancy sensor connected to the light seems to work fine. When someone enters the room the light turns on and then turns off after the set period.

The exhaust fan on the other hand does not turn on, not even manually when the switch is pressed. I assumed that I wired something incorrectly, so I took off the fan cover, unplugged the fan from the receptacle and plugged in a lamp. The lamp worked fine and I was able to control it with the switch. I assumed my exhaust fan motor failed and bought a motor upgrade kit (Broan EC60KIT). After replacing the fan motor, the new motor turned on via the switch, but seemed to be running slower than usual and then just stopped working. Now the new fan has stopped working too.

I plugged in a multimeter into the outlet at the fan box and it fluctuates between 10 and 120v, maybe because I can't turn on the switch without a load?

Before I go out and get another fan, how can I check that my switch wiring is okay? It seems to power on a lamp without problems.

Put conventional switches back in the circuit and see if everything works fine without the OS. Get your wiring wrung out and get everything working. When that is done, start by replacing one switch at a time. (you said sensor(s), right?)
Does that OS switch require a neutral and do you have one present in the box?

Put conventional switches back in the circuit and see if everything works fine without the OS. Get your wiring wrung out and get everything working. When that is done, start by replacing one switch at a time. (you said sensor(s), right?)
Does that OS switch require a neutral and do you have one present in the box?

Thanks for your reply Missouri Bound. Unfortunately I forgot to check this thread before trying something else out.

Yes, I have two sensors. I haven't replaced the original switch back yet, but I double checked my wiring. There are four black wires in the wall box. I used a "Klein Tools" voltage tester and only one of the black wires is hot.

When I rewired the switches after checking, I connected the hot wire to the line on one switch as well as the wire that's stripped in the middle. I connected the stripped part of the wire to the second switches line and I connected the other two wires to the load on the two switches. I also connected a ground wire to each switch and connected the other end of the ground wire to the ground wire in the switch box. There was no pre-existing ground wire on the previous switch.

The light still works via the switch / occupancy sensor.

For the fan, I connected an extension cord to the exhaust fan outlet and connected a light and voltmeter to the outlets on the extension cord. When the fan switch is off, the voltage reads at about ~12v and when the switch is on it goes to ~104v. Everything looked OK, so I hooked up another fan. But again the fan motor was very slow, so I immediately disconnected it to prevent further damage to the fan.

I will reconnect the original switches this weekend and try to get the wiring correct. I thought I got everything correct after checking for the hot wire.

I'll report back here with my progress.

104 volts is not acceptable. Do more checking at other outlets. It's possible you have an open circuit somewhere.

What you have between the fan/light and the switch box is a switch loop. One wire brings current to the switch box (from the fixture box), one wire takes current back (through the switch) to the light, one wire takes current back to the fan.

Suggest that you remove the occupancy sensors. Do a voltage check between the hot and the ground. There is no neutral at the switch box, nor do you need one for the occupancy sensor, but you do need a ground.
Your meter should show 120V between the hot and the ground. That will confirm that you have the proper voltage and will also confirm that you have a good ground.

Assuming you have 120V between hot and ground, connect all three wires together with a wire nut. Of course the light and the fan should both operate. If they do then one of the occupancy sensors is defective.

Assuming that either the fan or the light does not function properly, do a voltage check between the wires returning current from the switch box and the neutral in the fixture. Also do a voltage check between these wires and the ground. These should, of course, show 120V.

Note, you may have a single neutral wire from the fan/light for connection to the house neutral or you may have a separate neutral wire for the light and another neutral wire for the fan. I suspect you have two separate neutrals. A poor neutral connection would explain the lower voltage readings and the slower fan.

I suspect you have either a poor neutral connection or a defective occupancy sensor.

Thanks for the replies. I checked the voltage at a few outlets around the house and they all show 120V. Is the white wire neutral? There are some white wires in the switch box connected with a wire nut.

After checking the voltage between the hot and neutral. If it is 120V, I will replace the switches with the original regular toggle switches and check the voltage at the fan outlet. If that's 120V too, then the switch is bad / incompatible.

I called Leviton tech support and they suggested the sensor may be incompatible with my fan. They suggested getting the ODS-ID10, but at $70, I'll get a Lutron instead.

Now I'm confused.
At first you said,

The wiring in the switch box is all black.

Now you say,

There are some white wires in the switch box connected with a wire nut.

Yes the white wire is neutral, that is most of the time. It can be used as a hot when wiring a switch loop or when wiring a set of 3-way switches. When used as a hot you are supposed to color each end black (put black tape on each end). However this is often not done.

If you have neutrals in the switch box you do not have a switch loop.

Describe the wiring in the switch box, all of them and how they are connected.


PRODUCT OVERVIEW

Model # R01-IPS02-1LI

Internet # 203865578



Leviton's IPV02/IPS02 Universal Vacancy and Occupancy Sensors combine state-of-the-art technology with new aesthetics to provide optimal management of lighting and motor loads and a choice of either Manual-ON (Vacancy Sensor) or Automatic-ON (Occupancy Sensor) switching.

Sorry about the confusion. What I meant by the wires in the switch box are all black is that only the black wires were attached to the original toggle switches. The white wires are there but connected to each other with a wire nut.

The wiring instructions for the IPS02 also show the neutral wires connected to each other with a wire nut and not connected to any switch, so I didn't touch them.

When I remove the switches this weekend I'll take pictures of the wiring in the switch box and how they're connect to the switches. I'll label the hot and load wires.

Don't buy anything as of yet. You need to wring out that wiring issue before you just start throwing money at the problem. The low voltage is the key to your problem. That low voltage is symptomatic of a few problems... you either have an open wire somewhere or you have tapped into a switch loop. You will need to start over and figure out exactly where each wire goes. The best thing you can do is put everything back the way it was originally and get it working. And as far as your "voltage tester" goes, it only shows the presence of voltage. You need to verify actual numbers, you need to determine which wires are switch legs and which wires are true neutrals. Like I said you should start over. Get someone to help you with the troubleshooting if need be, or at least someone to switch breakers off and on to assist you in tracing the circuitry. It used to work, right?

Sorry for taking so long to reply. I didn't get around to this last weekend.

I've solved the problem. I did as you said Missouri Bound, and put back the original switches and the fan worked just fine, meaning a switch problem or incompatibility as Leviton tech support said. I don't think the switch is defective, since I tried two already, it's just not appropriate for my exhaust fan.

Anyway, I just bought two Lutron Maestro sensors instead, an MS-OPS5MH for the exhaust fan and an MS-OPS2H for the lights. They seem to be working just fine. They are more expensive at more than double the cost of the Leviton, but they work as needed and look nicer.

Thanks for your help!

Good. I figured you would get it solved... a bit of patience and troubleshooting is worth ten trips to the hardware store.