I am really confused on how to connect this new dimmer to my bathroom GFCI outlet. This one has screws. Old dimmer stopped working and had wires.

New dimmer and outlet:

new dimmer and outlet

Outlet wiring:

outlet wiring

Both lights and outlet are working when line and load are both connected. I have 4 wires - 2 blue (1 hot), 2 white) and a ground coming out the box.

Not sure how to connect new dimmer with screws to this set up.

  • On your existing GFCI, can you figure out which set of screws is LINE and which is LOAD? (There should be markings on the back of the GFCI that tell you which is which) Jul 23, 2021 at 0:20
  • Is the light over the shower/inside the shower stall? Jul 23, 2021 at 2:35
  • @ThreePhaseEel - yes, I'm able to figure out the LINE and LOAD labels. Think the dimmer needs to be connected to the LOAD in some way, but not entirely sure. My old dimmer had wires and the new one has screws, so confused which way to go.
    – Kevin W.
    Jul 23, 2021 at 14:49
  • @Harper-ReinstateMonica - the light is over the sink. The wiring in the wall is just wonky and doesn't separate whats coming from the light and the line. That's my dilemma.
    – Kevin W.
    Jul 23, 2021 at 15:09
  • 2
    All current drawn from the LOAD "hot" must return to the LOAD "neutral". Otherwise the GFCI will trip. Current flows from hot, via the dimmer, via the light, back to neutral. Your light is not in a shower stall so it doesn't need to be GFCI. I would just not use LOAD. Jul 23, 2021 at 18:03

2 Answers 2


Assuming you have the correct type of switch...

You need at least 1 more wire nut and 3 more wires. The nut and 2 of the wires would bond all of the 3 grounding screws you would have after adding the switch.

The extra wire would connect the new switch to the hot load screw of the GFCI. The wire that was already attached to the hot load screw would relocate to the switch.

If your switch has more than 3 screws total, then you need to take a detailed look at the instructions to find out what else it needs.



  • One blue/white pair entering this box is power, the other goes to the lights. Per your comments the "lights" one is the one with the red wire.
  • You connected the lights to the LOAD side of the GFCI when you removed the dimmer, so they are permanently on now.

If the assumptions are wrong so is my answer. But if they are wrong, I can't see what the dimmer might connect to regardless of screws or wires.


  1. Remove the wire nut. Connect the now-loose red wire to the gold terminal of the new dimmer and the blue one to the black terminal.
  2. You need an extra bit of green or bare wire, connect the green screw on the dimmer to the one on the back of the box where the green wire is attached. Don't remove the existing one.
  3. If you don't want the lights to go out when someone drops a hair dryer in the sink, and if you are allowed to have the lights non-GFCI-protected, move the red and white pair from the LOAD terminals to the corresponding LIVE terminals of the GFCI, where there should be a second pair of holes to accommodate them.

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