I would suggest getting an inexpensive voltmeter (Home Depot) so that you can check that your getting power to your new dimmer and have connected it properly. Be careful though if your not experienced. Based on what you have described, I would guess that you have reversed the black (120 volts) and the red (load - light) leads coming from your house wiring. Usually there is no red wire in your house wiring, only two black wires (one is 120 volts and the other is going to your light. But, don't just try swapping them, a simple voltmeter will help tell you which is which. If you don't feel comfortable doing any of that then you probably need to get an electrician.

CecyAriz wrote

Hi!
 

I hope someone can help me. I am trying to install a new kasa dimmer. I have identified all cables (black, red, white and green) from my old switch but when I connect the new dimmer, it won't turn on (no wifi, no light indicator).

 

I can't say is the neutral cable as I have another Kasa switch (not dimmer) connected next to it and it is working fine. I have even returned 2 switches thinking it was them but so far no luck.

Any ideas on what might be happening?

Thanks!

@flipflop49 thanks... Everything looks fine, if the old dimmer is plugged, it works, but as soon as I connect the new one, there is no wifi indicator, so I can't add it to my kasa app.

Also, I have a regular kasa switch next to it working (connected to same neutral).