Computer Fan

May 20, 2010 5:43 PM

If I bought a computer fan with 2 wires coming out, what do I have to do besides hook up power to those wires to make it spin?

I bought this fan. It's model # is FAN-AC-12388.

I bought it to replace a fan in a bug killer that went dead, it's the same size fan, with roughly the same power requirements, but when I hook it up, nothing happens. I know there's power going to it, it just won't spin..

Any help would be greatly appreciated.

posted by jjbb to Computers & Internet (11 answers total)

check your motherboard manual for any jumpers that would need to be changed.
Also check BIOS settings.
This are just ideas, I can't remember if I had to do such when I installed a second fan in my computer.
posted by spacefire at 5:50 PM on May 20, 2010

Best answer: Do you have a multimeter? Computer fans, I think, use 12V DC but aren't very picky. Can you check what voltage is across your wires, and if it's DC or AC?
posted by alexei at 5:52 PM on May 20, 2010

Best answer: The fan you linked to is a 115 volt AC fan. As long as the one you're replacing is also a 115 volt AC fan, hooking up the two wires should be all you have to do. If the one you're replacing is not roughly 115 volts, or is a DC fan, then this one isn't going to work at all.
posted by FishBike at 5:56 PM on May 20, 2010

Response by poster: Thank you Alexei Fish. This was driving me crazy. The old fan is DC, so that's the problem.

So... there's no way to make this work right? I just need to go find a DC fan?
posted by jjbb at 6:03 PM on May 20, 2010

What's a "bug killer"? Is that a cute name for your computer? Because this thing isn't really a typical computer fan, which are designed to be plugged into the computers power supply. Your fan runs on North American AC line volatage...
posted by mr_roboto at 6:06 PM on May 20, 2010

Response by poster: A bug killer is this neat little device that has an LED light to attract mosquitoes and such. When the get too close, a 120mm fan sucks them in and chops them to bits, and deposits their insect dust in a nice little bin.
posted by jjbb at 6:09 PM on May 20, 2010

I just need to go find a DC fan?

Yup, DC fan and of the same voltage as the old one. Voltage should be marked on the old fan someplace. Ideally you would also match the airflow in CFM (cubic feet per minute)... if the old one has so many CFM marked on it, try to get a new one about the same CFM. Wires are also usually colour-coded red for positive and black for negative, and you might have to make sure you get the wires the same way around when installing the new fan. Some DC fans don't seem to care about that, but some do.
posted by FishBike at 6:10 PM on May 20, 2010

Yup, DC fan and of the same voltage as the old one.

And close to the same amperage, for example, 0.15A. Amperage is closely related to RPM for a given voltage fan.
posted by JackFlash at 6:27 PM on May 20, 2010

Response by poster: Another question, the fan I'm replacing is a 2 pin fan. If I were to buy a 3 pin fan and just omit the ground wire (that's the 3rd wire, right?) and just splice it into a 2 pin connector, that should work. Correct?
posted by jjbb at 6:45 PM on May 20, 2010

The 3rd wire (typically yellow) is for monitoring fan speed. Just leave it disconnected.
posted by zsazsa at 6:53 PM on May 20, 2010 [1 favorite]

Wires are also usually colour-coded red for positive and black for negative, and you might have to make sure you get the wires the same way around when installing the new fan. Some DC fans don't seem to care about that, but some do.

This is becuase some fans contain a very small circuit board with a controller and are not simply a motor.
posted by Big_B at 1:15 PM on May 21, 2010