I have a Beamswork LED aquarium light like this. It has a 3 way switch:

  • All LEDs off
  • Blue LEDs on only
  • White AND blue LEDs on

It has a single mains power plug.

What I want to do is make it have two mains wall plugs. I want one to power the blue LEDs all the time, always on.

I want the 2nd plug to power the white LEDs only, and this will be plugged into a plug timer like this, so the white LEDs will independently go on and off by time, while the blues stay on (because that will be plugged in separately - I hope).

I opened the cover and found this:

enter image description here

The 2 black wires connected to the brown PCB is where the mains adapter plugs into. Then there are 3 blue-covered connectors which are connected to the 3 way switch. I don't know which ones control which colour as I didn't test it plugged in, but I think the white one is white LED, the middle one is power, the one I'm holding had a blue wire so probably blue LED. Is there a way to connect a 2nd mains plug to that blue LED connector (if it is that) so it powers separately? Drilling through the plastic to get a wire in is fine, but I don't know how what electric connectors or connections I need.

I don't know much about electrics, first-time project! Thanks.

EDIT: This is is the spec of the adapter:

enter image description here

And here I have done a few tests:

enter image description here

  • Wire 1 controls the "blue ONLY" LEDs from the switch
  • Wire 2 comes from the mains adapter
  • Wire 3 controls the "white AND blue" LEDs from the switch
  • Wire 4 goes to a metal thing on the LED board saying "Ground"

If I disconnect wire 1 and put the switch into the "blue only" position, the blue LEDs don't come on. But if I put the switch into the "all on" position, the white AND blue LEDs do come on.

If I disconnect wire 3 and put the switch into the "blue only" position, the blue LEDs do come on. But if I put the switch into the "all on" position, the white AND blue LEDs don't come on.

I'm thinking of getting a second power adapter and a male connector to fit directly to wire 1 (so disconnecting wire 1 from the original switch above), so I can keep the blue LEDs always on. But I'm worried, since wire 3 turns on both the blue and white LEDs (even if wire 1 is disconnected), will this make the blue LEDs get double power and cause a problem?

My goal in the end is to have the blue LEDs always on (because they will be powered separately from a new mains adapter) 24 hours a day. And the white LEDS (which also turn on the blue LEDs too) to be plugged into a plug timer and turn off at certain times of the day. Any suggestions?

  • \$\begingroup\$ Without a picture of the circuit board, and the label on the mains adaptor (ie, wall wart), it would be hard to suggest anything. To separate the two would require creating a second circuit in any case. Pictures are a must. \$\endgroup\$
    – Passerby
    Apr 11, 2013 at 23:24
  • \$\begingroup\$ This could be a real simple modification too. \$\endgroup\$
    – Passerby
    Apr 12, 2013 at 0:30
  • \$\begingroup\$ Thank you all for your replies. I have updated the original with more pictures and some results of tests. \$\endgroup\$
    – nLinked
    Apr 13, 2013 at 21:30
  • 1
    \$\begingroup\$ to answer your question, we would need a picture of the board where the white and blue wire go to, preferably on both sides. \$\endgroup\$
    – Passerby
    Apr 14, 2013 at 0:10
  • \$\begingroup\$ Someone in this thread had the same idea: plantedtank.net/forums/showthread.php?t=168242, and apparently it works fine. \$\endgroup\$
    – gwideman
    Apr 9, 2014 at 9:39

2 Answers 2


This is only an educated guess given the pictures and description. You need to do more testing and convince yourself that this works.

It looks like you could take wires 1 and 2 and connect them and get blue LEDs only, and 2 and 3 and get blue and white LEDs. if this is true you could buy a little timer relay kit from any electronics hobby store and connect it between wire 3 and what wire 3 plugs in to. Set the switch to "blue only" and leave it in that position, using the timer relay to do the white+blue cycle as you want.

  • \$\begingroup\$ > connect it between wire 3 and what wire 3 plugs in to. What does this mean? I think the relay would have to go between wire 2 and wire 3. It looks to me like downstream from this switch the blue and red wires have diodes connecting them to the blue LEDs (so that each can power the blue LEDs without the blue function also powering the white LEDs), and the red wire is also directly connected to the white LEDs. So having he relay result in 1,2 and 3 all connected should be fine. That said, finding a convenient timer relay to switch this DC, off the shelf, might be challenging? \$\endgroup\$
    – gwideman
    Apr 9, 2014 at 9:46

If the three "blue-covered connectors" go to the control switch then it is likely that your neatest solution will be to "force" the blue LEDs always to be on by permanently having the blue-led wire connected to the power feed into the switch. Forget about having seperate power plugs on the wall - that sounds messy to me.

I don't know how adept you are at rewiring the switch but if it were me doing it I'd purchase the mating halves of the blue-covered connectors and work on it this way.

Be very aware - I don't know what voltage is on these wires - it could be low voltage and therefore safe or it could be a higher voltage. You mention that there is a mains adapter but this may still generate a big voltage and/or get warm and pose a fire hazard should it be incorrectly connected to something. Take care is the watch-word

  • \$\begingroup\$ Thanks, however, I want the blue LEDS to be on 24 hours a day, while the white LEDs should only come on according to the times set on the plug timer. For this goal I would unfortunately need a second plug :( \$\endgroup\$
    – nLinked
    Apr 13, 2013 at 21:36
  • \$\begingroup\$ @nLinked - did you mention the plug-timer in your origianl post? \$\endgroup\$
    – Andy aka
    Apr 13, 2013 at 21:55
  • \$\begingroup\$ @Andyaka yea it was in the original post. \$\endgroup\$
    – Passerby
    Apr 14, 2013 at 0:12

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