Adding Fans

I was wanting to add three fans to my 360 rad in my duel loop. I was using Y splitter to run 2 fans off of one of the MB case fan pins. Problem is I could get two  to work but when I tried to add a second, only one fan would turn on. The second fan would start then stop.

if they're loud, don't get those cables lol, just rewire the molex connector to undervolt the cables.
 
Molex 101
red = 5v. yellow = 12v. black = ground. you need to connect a powered cable to a ground cable to complete the circuit. if you want it running a little quieter, you can use the molex to 3-pin adapter andy posted, and adjust what cables the fans take manually. all you need is a small flat-head screwdriver to rip out a molex connector. to rip it out, just look in the head of the connector for the pin you want to get out. you should see two fins jutting out of the pin opposite each other on that pin. use the small flat head screwdriver, and gently nudge them toward the pin itself so it's completely circular. then just pull it out. to reattach it, have the pin in hand, and gently pull them out again, and stuff the pin into the hole you want. normally, the fan would run 12v, as in, yellow and black in the circuit. to run it at 7v, leave the 12v yellow cable be, and remove the black cable. now, remove the red cable, and insert it into where the black cable was. it's now running on a 12v -> 5v circuit, and it interestingly produces a 7v current. if you want it running even quieter, you can make it run at 5v. to do that, remove the 12v yellow wire, and leave the black in place. now, put the 5v red wire into where the 12v yellow wire was. 5v -> ground = 5v current. that's essentially what the other cable andy suggested does, i think.

Hmm loud is not the issue fans are Typhoons. This is a power issue. I am out of MB plugins.

Ordered, thanks