Custom wiring (easy question)

[m3rcury]

I have a cpu fan with a 3 pin connector and I want to connect it directly to the PSU. The 3 pin connector has a black (ground?), red and yellow wire, and the 12/5 volt connectors from the PSU (the standard ones) have the same colored wires. My question is what volt is the 3 pin connector supplying to the fan and can i directly connect the corresponding colors from the 3 pin to a standard molex (i'll be solering them) that comes from a ATX PSU?

Thanks.

 

[lenjack]

12 volts to the CPU fan. Yellow is 12, red is 5 & black is ground. Yes, you can connect it the the power supply 4 pin molex, but you will not be able to read fan RPM, unless connected to the board.

 

[Scott1]

For any fan with a RPM sensor:

Yellow = RPM sensor
Red = +12V
Black = Ground

You can get a 3 pin to 4 pin molex adapter just about anywhere that sells case fans.