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Adapting 3-pin connectors to 12V?!

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New Member
May 24, 2001

I bought a bunch of fans to cool my system, and they all need those little 3-pin connection to my motherboard. Unfortunately, my SuperOrb takes up the only 2 3-pin connectors I have. Are they doomed? Am I a simpleton?! I think so!! Anyway, if any of you people have any ideas for me, I'd be appreciative!!

You can buy adapters that those little 3-pin plugs go into that then plugs into a conventional 4-pin molex connector, like those coming from you PSU. Obviously, if you don't have any of them available either, then you got to break out the strippers and soldering iron.

I'd suggest you buy or build a fan bus or bay bus to hook up and/or control all your fans. You can find the information at http://www.fanbus.com Specs, details schematics and pics are available, and this is the guy who designed the original.
Or if you want to really keep it simple, Cutt the ends off and stick the bare wires right into the free molex connecters from you PSU. Black is ground, Red is 5v, and yellow is 12v (you may have already new that). Just make sure you tape them good so they dont fall out and short something out. I did this quit a bit untill I built my BayBus.

I know I can be pretty damn lazy at times!
If you haven't hacked the wires up yet, there's an easier, non destructive way....

On the back of the 3 pin plug, are three little slots. Get something like a small screwdriver (I used a toothpick) and push it into the slot gently. You are pushing down on the metal tab that secures the wire terminal in the plug. Push gently, while pulling on the wire to remove it from the plug. Remove the black, and red only. Leave the blue wire in the plug.

Take the black wire and push the terminal into the open end of a black wire in a 4 pin socket coming from your PSU. Push the red wire into a yellow wire for +12v, or red for +5v. Now, take the blue wire (fan monitor-rpm sensing) still in the plug, and plug this into the 3 pin motherboard fan power socket.

Your fan is now running powered directly from the PSU, and you still have monitoring capability. Plus, you can put the wires back into the fan's plug if you need to in the future.

Mr B
i agree with Mr. B's tip. I did the exact same thing, and saw a nice performance jump. I had a delta running on the MB at 5400RPM. Not so hot, but now, with the 12V hooked in, I get 7300RPM!!!! The way I attached them was to use an old 40mm fan that was connected via a molex passthrough. Just cut the fan wires off, stripped them, wrapped around the two connectors on the delta, and taped together. Its beautiful!
Should have read this thread before doing what I did this morning. I cut out the black and red ends and connected them to a molex connector from the psu. I just taped the rpm monitoring wire. Was this wire supposed to draw current? Is my intake fan slower because of what I did?