yea you can. I did the same in my case. I didn't have any Y Splitters for my fans. So i just made one. Got the end that plugs into the Motherboard, then got the two female ends and made it myself. Just match up the wire colors. usually they are Black, Red, and White (Sometimes yellow) if you are unsure of the colors just match it up with how the fan plugs into the power connectors on the motherboard or 4 Pin Molex Adapter what ever the case is you are using.