4 Pin fan Molex with only 2 Pins?

Gazuba

Reputable
May 5, 2015
2
0
4,510
I bought a cheap case for a first build and it came with 3 x 120mm case fans. My confusion is that the case fans have regular 4 pin molex connectors, with only 2 pins in them. There's no yellow wire, only a red and a black one. Ive tried connecting them to the molex's on the PSU, but the 2 pin connectors dont line up with the correct pins on the PSU molex.

I would appreciate any advice, and I apologise if this is obtuse.
 
Solution
The red wire is for +5V. The black wire is for ground or negative. If the fan was connected to 5 and 12 volts, the fan would probably be fried, and you would need a new fan.