I'm trying to replace old dimmer and timer (sitting side by side) with new Leviton dimmer and Lutron timer, however the box got me confused as it appears all neutral white wires are tied together in one nut and are not attached to anything - please see picture. There are also white wires coming out of top and bottom on the left switch..How do i go about connecting the dimmer and timer? Dimmer has ground (green), red and black. Timer has red, ground, white and black wires.

On the left dimmer - I tried to connect red wire from new dimmer to red and black from the box (circled top left on the pic in red/black).

I also connected black wire from the box (circled in black) to black wire on the new dimmer.

On the timer on the right - I connected black wire from box (circled in black) to the white wire on the new timer and then I connected black wire (circled on the bottom left in black) to the black wire on the new timer.

I also connected red wire from new timer to red wire on the dimmer switch on the left as there is no red wire coming out of the box on the right for some reason.

Grounding wires (green) both are connected to each of the box's screws - on the left and right of the pic.

When I made connections, i lost some power in nearby locations i.e. bathroom and some kitchen outlets.

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  • Can you post the model numbers of the dimmer and timer, and a photo showing how the switches are wired? Aug 31, 2019 at 15:29
  • Dimmer is Lutron Diva DVCL-153P and timer is Levitron Decora Vizia 24-hour programmable timer,Model # VPT24-722 Aug 31, 2019 at 16:22
  • Do you have a voltmeter or non-contact tester? Aug 31, 2019 at 16:31
  • Yes I have a voltage tester pen Aug 31, 2019 at 19:22
  • Can you use it to figure out which wire power comes into this all on? Aug 31, 2019 at 21:02

1 Answer 1


It appears like you wired your neutral wire on the leviton switch to your hot or load wire in the box. The white wire on the leviton switch is a neutral.

Smart light switches like leviton switches require a neutral wire to operate to provide power to the timer chip constantly. The white wire on the switch should be wired to the white neutral wire in the box. Non smart light switches didn't require a neutral that's why they are just tied together in the back of the box.

Connecting the hot or load wire to the neutral wire as you have done with light switch on the right can be dangerous as that is not how the switch is designed to operate. If you're uncertain of the wiring it's probably not a bad idea to get an electrician or a friend that's familiar with electrical to help you out. That being said you can fix the issue.

I would recommend replacing both of your switches with Lutron Caseta switches which would allow you dimming control, allow you to remotely set a schedule or timer from your phone and would be less confusing to install.

Without an existing picture of how the orginal light switches were wired it's hard to diagnose which wire is the hot and which one is your load wire (the one that goes to the light fixture)

The advantage of the lutron caseta light switches is that they don't require a neutral wire and they wire up just like your old switches and if you wire the hot and load wire backwards it won't matter. Which makes them easier to install.

So on the left you would wire the new lutron switch with the red wire and black wire. On the right you would wire the two black wires to the new switch. And both new light switches should have their grounds properly terminated which it looks like you have done in the original installation.

I found this smart light switch installation guide: helpful with videos that show you how to install the lutron caseta style light switches with no neutral.

Disclaimer: I don't work for lutron but in this situation I think it's good solution for a DIY fix to the current wiring situation with the information provided. See comments below for more details.

  • MK- thanks for the heads up, there are plenty of other smart light switches that would work with the commenters lighting. But given that the poster wired the neutral wire on the light switch backwards to to a hot or load line it doesn't seem like a good idea to recommend a more complicated switch setup. I also have no idea how the orignal switch was wired, so without knowing which wire is the load line and which is the hot line which can't be determined from the picture above. It doesn't seem like to a good idea to recommend a switch that requires proper orientation of these hot and load wire. Sep 8, 2019 at 6:49
  • The Lutron light switch can be wired without the needing to know which wire is hot and which is load as long as one wire is wired to a hot and one is wired to a load wire it will work. An electrician in person could quickly diagnose which wire is which using a multimeter. My intent was to offer a solution to the poster that would not require additional electrical knowledge and could safely be completed in DIY manner. Sep 8, 2019 at 6:50
  • That's fair point, and I appreciate the heads up. After re-reading it I get where your coming from. I added a disclaimer. If the poster wanted to use the existing light switches and correct the work they could do the following. 1-Get a multimeter and test which wires are hot wires and which wires are load wires. The would do this by taking a picture of the existing wiring, then pulling the switches forward and the white wires in the back (neutral wires) and pulling them forward. They would then remove the wire nut while keeping the white wires twisted together. Sep 8, 2019 at 7:01
  • Then take their multimeter and test each wire by putting one end to the neutral and the other to the what is presumed to be the hot wire or load wire. The hot wire to neutral would read 120V and the load wire to neutral would read 0V. There is also the possibility that when the poster removed the existing switches they disconnected a hot wire that was feeding current to a light switch and lights further down the system. In which case they would need to determine which wire that was and reconnect it to the other hot wires within the box, and then connect the hot wire on the switch to the group Sep 8, 2019 at 7:05
  • of other hot wires. Sep 8, 2019 at 7:07

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