Is it normal that 12v lighted rocker switches get hot even when the load is not connected? Attached is the schematic and the PCB layout for such switch: https://lcsc.com/product-detail/Rocker-Switches_ROCKTEK-RT-S02-113-R42BR_C309263.html

The switches get very hot, the ones with more load get even hotter.

enter image description here(VCC is 12V) enter image description here

  • \$\begingroup\$ ones with more load get even hotter makes sense if the contacts are being overloaded \$\endgroup\$
    – jsotola
    Commented Apr 19, 2020 at 3:10
  • \$\begingroup\$ @jsotola it can burn one's finger when there is not load. The led itself shouldn't overload the contact the switch. \$\endgroup\$
    – RoastDuck
    Commented Apr 19, 2020 at 3:25
  • \$\begingroup\$ it is unclear if the indicator is an LED ... pins 1 and 3 are probably shorting internally ... check the switch with an ohmmeter \$\endgroup\$
    – jsotola
    Commented Apr 19, 2020 at 3:33
  • \$\begingroup\$ datasheet says: "The usable lamp life has not been evaluated". lol Now you know why. SCNR. I recommend measuring the current through the lamp and maybe reduce it by adding resistors or diodes to the ground pin. \$\endgroup\$
    – Ariser
    Commented Apr 20, 2020 at 5:24

1 Answer 1


You say "12V" in your title, and "12V" in your message, so presume "12V" is not a typo. But the datasheet you linked (which matches the part number on your schematic) clearly indicates that switch is meant to run it's light from 125V...

Meaning - You got the wrong datasheet

If the datasheet/part number are wrong, perhaps something else is wrong too.


Suppose you think you have a 12V drive lamp, but it's really meant to be driven on 5V. That'd explain why it gets so hot.


The pinout isn't what you think it is


Just take one of the switches apart. They're not magic. You'll figure out quickly by examining the mechanism if the switch is different from what you expect.


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