I'm new to this kind of DIY stuff and I need help with the wiring of this light switch.

The old light switch (left picture) has L1, L2, Common in both sides. On the new switch (right picture), it has an L1^1, L1, L2^1.

As you can see, the old switch has 3 wires, and 1 bridging(?) wire.

I've highlighted which is the off side and on side on the old one, but I can't figure out where to put these wires properly on the new switch.

Any and all help will be greatly appreciated!! Thank you enter image description here enter image description here

  • 1
    Where are you on this planet, and what make and model is the new switch? Commented Mar 22, 2021 at 11:43
  • Your third photo is worse than useless -- it is misleading. Half the internal parts are missing, and of the remaining, one part (from upper right in the photo) fell out and you put it back in the wrong place (upper center). - The photo is not needed anyway, I suggest you just delete it. Commented Mar 22, 2021 at 18:43
  • You shouldn't be using that switch at all. Note the CCC logo molded into it. That, in absence of a more proper mark, basically stands for "Cheap Chinese Crud". Not safe or legal. You need stuff that is competently approved by an independent testing lab, like BSI, TUV or UL. CE might be acceptable if you bought it at a quality bricks-and-mortar store, like Wickes, but CE is meaningless when bought mail-order because it bypasses the regulatory scheme that makes CE mean anything. You will probably find quality switches are properly marked. Commented Mar 22, 2021 at 19:30

1 Answer 1


The old switch

Strictly speaking, you need to find out what those three wires are connected to. If I had to guess, though, I'd feel quite confident that the wires are as labeled here:

old switch best guess

The bridging wire (called a "jumper" in my world) tells the tale. The power supply is the only wire that would be connected to both switches, and thus to two terminals, and thus need a jumper.

The previous sparkmonkey's choice of terminals gives one pause, but the circuit works. The gauge of the jumper is too small; it should match the load wires. And you should check that your local code allows two wires to be crushed into one terminal.

The New Switch

You should consult the documentation that came with the switch; there should be a diagram showing the purpose of each terminal. If I had to guess, though, I'd feel quite confident that the terminals are apportioned to the switches like this:

new switch best guess

L1 is switched between L11 and L12. L2 is switched between L21 and L22.

You must connect the power wire to L1 and L2.

If you are allowed to connect two wires to one terminal, then use one jumper. Make the jumper from wire of the same gauge as the load wires. Connect the power wire and one end of the jumper to L1, and the other end of the jumper to L2.

If your electrical code forbids two wires on one terminal, then use two jumpers and a wire connector (ie. wire-nut, Marrette, Wago, etc). Connect one jumper to L1, and the other jumper to L2, then use the wire-nut to connect the free ends of the jumpers to the power wire.

In any case, connect Load 1 wire to L12 and Load 2 wire to L22.

If this does not work, the one of my guesses is wrong, and you have some diagnostic work to do. In that case post a follow-up comment and I (or someone here) will guide you through the testing process.

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