A year or so ago, my PC’s fan was making an unacceptable amount of noise, so I changed it. For the most part I’ve been pleased with the new fan, but I kept the old one since it still worked, just in a louder manner than I wanted. I was cleaning up the garage, and found it again, just waiting to be thrown away, since I wasn’t sure how to hook it up.
Well now I know. After some simple experiments seen in the video below, all you have to do is run between 3 and 12VDC between the red (positive) and black (ground) leads. It couldn’t be simpler, and might make a good fan for blowing fumes away while soldering, or just trying to cool off during the summer.
The 3V supply worked, though didn’t blow much air. Perhaps a portable version would use a 9V battery.