Instructables

Computer Molex Power Y-Splitter

Picture of Computer Molex Power Y-Splitter
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Many people out there have undoubtedly found themselves in a situation where they need to plug another computer component into their power supply but have run out of plugs. You think to yourself "jeez, I need more plugs!" Well, here is the solution.

Using parts from an old power supply and a case fan, I've built a Molex Y-splitter. I've seen these retail for around $4 (more if you take shipping into consideration). The parts I used were leftovers - total cost of $0.00.
 
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Step 1: Materials & Tools

Just a friendly reminder: Always know the proper use of any of your equipment - read any manuals and take all safety precautions. Safety glasses are recommended in just about any endeavor including tools, so if you think you need them, WEAR THEM. I am not responsible if you hurt yourself attempting this mod and I hope you don't. I managed not to burn myself with the soldering iron this time, so go me!

Materials:
  • Leftover (male) power plugs from old power supply
  • Female molex plug (mine was from a case fan)
  • heatshrink (or electrical tape, if you don't have it)

Tools:
  • Thin-nosed plyers
  • Wire stripper
  • Incredibly tiny flathead screwdriver (like the kind you find in a eyeglasses repair kit)
  • Soldering iron and solder

Step 2: Remove the Pins

We have to take the pins out of one of the male plugs and the female plug. Take your small flathead and depress the tabs on the side of the pin (see picture). There are two per pin. Then just pull the pin out and continue.

Step 3: Remove the Pins from the Wires

Now take that flathead again and start prying up the clamps holding the wires to the pin. Once you get them off, flatten the clamps and snip the wires as flush as you can. Remove any of the plastic shield that might remain. Do this for all eight of the pins.

Step 4: Reattach the Pins for the Male Plug

Now we have to attach the pins onto the right wires.

By now you should have a set of four wires that have no plug attached. Use the wirestrippers to remove about a centimeter of sheath from each wire on one end of the bundle. Now take the pins from the male plug and bend the clamps 90 degrees like in the picture. Use the flathead to push the locking tabs back out of the pin. Then bend the clamps to hold the wire on and solder the wire to the pin. This is much easier if you have one of those soldering "helping hands" stations (believe me).

When you've got all four pins reattached, you might want to put some heatshrink on. Or not - depends on what you want. Put them back in the male plug, making sure they are arranged in the same pinout as the other untouched male plug you have.

Step 5: Attach the Female Plug

Now we have to attach the female plug to complete the y-split.

Strip about 7mm of wire from the untouched ends of the wires left. Twist together the like colors (make sure you have the black wires paired up correctly!) and attach them to the pins just like you did with the male plugs. You can tin the twisted pairs if you want (and if you know how to do it right, unlike me) if that makes it easier for you. It didn't help me.

You will probably want to put some heatshrink over the pins where they connect with the wires. I put my pins back into the plug and had metal sticking out, so that's why I did it.

The easiest way to make sure you have the pinout right is to plug the empty female plug into one of the male plugs and line up the wires that way. Again, make sure you have the black wires lined up correctly. When you push the pins in, make sure the tabs clicked out to lock the pin in the hole.

Step 6: Finished!

Picture of Finished!
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You now have a Molex Y-Splitter. Hooray for having more plugs.

Just make sure you don't overload your power supply with all the extras you might add ;-)
ichibon5 years ago
fantastic post
westfw6 years ago
Nicely documented and written. But... Why did you go to the trouble of disconnecting one of your "male" connectors; they were already wired together and you should have been able to just attach the "female" connector to the loose end. It wouldn't have LOOKED like a "Y", but it would have been the same electrically, for all practical purposes. I would have sexed the connectors based on the shape of the pins rather than of the housing, but consistency is good enough.
frazeeg (author)  westfw6 years ago
Actually, that's a great point. I didn't really think about it until now, but everything's running in parallel either way you hook it up. I think I like it better this way because to me it just seems to take up less space and make less clutter in the box. Of course, you can minimize the wire clutter with some zip ties and make it the same either way. Oh well - I just like playing with this stuff :-P
cool, but i dont need this cause i got a 700watt psu with many molex adapters :-D