3pin vent splitter

[Ady20]

So I have a 120mm vent at the front of the PC, and 1 80mm vent that takes the air out. I only have 1 3pin connector on my MB.
I found in my box of "goodies" a 3pin splitter. 1 end has 3 cables(yellow, red, black) and the other end only 2(red,black).
My question is witch vent to connect on witch end. If I connect a vent on the 2 cable end only it won't work at max capacity? Because red is 5v and yellow is 12v...or something like that? Excuse the dumb question but I'm not a pro.

And thank you a lot for the upcoming replies.

 

[inerax]

I would get a new cable that is designed for this, I honestly cannot picture what you have.

You can get 4 pin molex and go straight from the power supply to the fan.

http://www.ebay.com/itm/3Pin-4pin-Male-Splitters-Transform-Cable-Connector-For-Computer-Fan-4Pin-Male-/281436574916?pt=US_Networking_Splitters_Couplers_Adapters&hash=item4186ed54c4

Or you can get a 3 pin splitter. Link below

http://www.ebay.com/itm/3-Pin-Computer-Case-Fan-Y-Splitter-PC-Power-Adapter-Cable-w-Black-Sleeve-6-/111444492345?pt=US_Power_Cables_Connectors&hash=item19f29c0039

 

[Ady20]

I have this cable: http://www.e-datacomputer.ro/watermark.php?src=ZGF0YV9maWxlcy9wcm9kdWN0X3Bob3Rvcy8yNzkyL2xhcmdlLmpwZw==

 

[inerax]

That should work fine. Give it a shot. I use one of those right now to control my fans in the back of my case.

 

[ewok93]

That's fine, the yellow is just a ground. Black is negative, red is positive.