I'm not too confident with electronics and I'm currently working on a project where I need a 12V mains power supply. I got a switch for it and have wired it. I've shown pictures.

Is this wiring correct? I'm confident it is, but need someone to check.


photo showing rear of switch and wiring

photo showing front of switch and wiringenter image description here

  • 2
    \$\begingroup\$ What does datasheet show? \$\endgroup\$ Commented Aug 4, 2018 at 0:40
  • 1
    \$\begingroup\$ Please show us the datasheet for the power entrance module. \$\endgroup\$
    – DoxyLover
    Commented Aug 4, 2018 at 0:53
  • \$\begingroup\$ Didn't get one unfortunately. Neither on the supply or switch. I follow3d a YouTube tutorial this far but I wanted a second opinion \$\endgroup\$
    – Stephen
    Commented Aug 4, 2018 at 1:01
  • \$\begingroup\$ I'll mention (in case it isn't obvious) that this setup is highly dangerous if used outside of a suitable enclosure, due to the exposed mains voltage on the rear of that power entry connector / module and on the power supply. Also, just FYI, I was taught to also crimp the insulation on spade terminals around the wire, to act as strain relief. \$\endgroup\$
    – SamGibson
    Commented Aug 4, 2018 at 1:07
  • \$\begingroup\$ Use a multimeter or reference document to determine which pins go the the indicator light, which to each side of the switch, and which to each of the pins in the receptacle. It's not clear from your pictures. Tell us this and we can give you a good answer, tell us what you're planning to mount this inside of and we can probably give you a good idea of how to make sure it's safe. \$\endgroup\$
    – K H
    Commented Aug 4, 2018 at 1:17

1 Answer 1


You seem to have wired it correctly.

enter image description here

If the switch indicator lamp stays on independently of switch position then swap the input and output wires on the switch.

  • \$\begingroup\$ Could you, please, clarify this: "If the lamp stays on independently of switch position then swap the input and output wires on the switch." Because I don't see how it is possible and what swapping wires could achieve. \$\endgroup\$
    – Maple
    Commented Aug 4, 2018 at 10:02
  • \$\begingroup\$ As shown on my overlay the indicator lamp is on the "lower" side of the switch. If you want the lamp to switch on and off with the load then the load should be wired to the lower terminals and mains to the other pair. If you swap the wires from the top to the bottom terminals the indicator will be powered all the time regardless of the switch position. Does that make sense? \$\endgroup\$
    – Transistor
    Commented Aug 4, 2018 at 10:11
  • \$\begingroup\$ Oops.. brain fart, sorry. I thought you meant connecting external lamp to those terminals to check if switch is wired properly. \$\endgroup\$
    – Maple
    Commented Aug 4, 2018 at 10:25
  • \$\begingroup\$ Oh this would explain why I find 2 different wiring diagrams when I search Google. Thanks a lot!! \$\endgroup\$
    – Stephen
    Commented Aug 4, 2018 at 16:45
  • \$\begingroup\$ OK. If that completely answers your question then please accept the answer to mark it solved. Otherwise wait a couple of days to encourage other answers and choose the best if you are completely satisfied. You can upvote as many as you think are helpful. \$\endgroup\$
    – Transistor
    Commented Aug 4, 2018 at 16:48

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