I am trying to wire a 120mm fan to a power supply but ran into a bit of a road block. I was expecting two wires from the PC fan but there are three... Any suggestions? Thanks!
After some research I found that the yellow wire is simply for a fan speed control which is not necessary. So I hooked up the red and black and bingo it worked. Just to let everyone know, the first time I tried hooking up the red and black they did not run. It DOES matter which wire the red and black go to. Not exactly sure how to distinguish the right ones. I just know that there is a right way and a wrong way. Thanks!
The black and red wire are the only ones you're working with. Just plug the power source in, (be careful) and put the exposed ends of the power cord to the fan exposed wire ends, and see which position gives it power. Then, unplug it, and electric tape the red and black wires to their correct wire on the power cord.
the 3rd wire is a neutral. it can be left unconnected or grounded. red and black are most important. typically the wire from the adapter that has the solid bars on it is the negative. moon biter is right..plug it in, hook it up. it is not going to put enough power through to hurt you. good luck