# how to wire cpu fan to electricity??



## sayurasem (Jun 17, 2011)

I have problem cooling my tank cheaply! so I read threads and chose to use one of my computer cooling fan.

so.... how to make the fan spin guys??? I need help... thx!

-btw, my fan has 4 wires.... so im like wth... I thought theres only 2 wires for everything.


----------



## RandomMan (May 31, 2011)

2 of the wires are the power, the other 2 are probably for a controller, so your computer can regulate the fan speed.


----------



## GeToChKn (Apr 15, 2011)

Red and black is all you need. Find an old power adapter from something like an old cordless phone, radio, something that is rated 9-12v.


----------



## IxIBluepitIxI (Jan 25, 2011)

To expand on the power adapter I would throw a switch from radioshack on the setup. Just solder the switch between the adapter cord and fan so you don't have to unplug it in and unplug all the time.


----------



## jasonpatterson (Apr 15, 2011)

The adapter will typically have 2 black wires (kinda like stereo cord.) The one with white writing on it is the positive, connect that to the red fan wire (solder + shrink tube/electrical tape) and the wire with no writing to the black.


----------



## redfishsc (Aug 29, 2010)

Agreed with the above, but I'll add two quick points. 

1) Make sure that your 9v to 12v (or any voltage in between) is rated to give at least 500mA, preferably 750 or 1,000. If your fan has a current rating given on it, just make sure your power supply is than capable of supplying the needed current. Some 9-12v power adapters are very low yield, most aren't.


2) Don't fret polarity. If you wire the fan backwards, it just blows backwards. No harm at all, just orient the fan to blow whatever way you want it.


----------



## sayurasem (Jun 17, 2011)

IxIBluepitIxI said:


> To expand on the power adapter I would throw a switch from radioshack on the setup. Just solder the switch between the adapter cord and fan so you don't have to unplug it in and unplug all the time.


SMART!! 

btw, I have green, black, blue, yellow....

man...


----------



## NatCh (Feb 23, 2011)

If the wires aren't identified by markings on the fan casing, or in any paperwork that came with it, just try them to see what works. You're unlikely to hurt anything if you stay within its rated voltage.


----------



## RSidetrack (Jul 17, 2011)

What is the MA rating on the fan? What I did for the canopy I just built is I got a AC to DC converter for car cigarette lighter socket items. It cost me $1.99 on ebay with free shipping. It's only rated for 650mA though, luckily my fan was 600 mA lol. Then what I did was took the Black and White wire from an old cell phone car charger that I didn't need anymore and hooked it up to the computer fans black and red wires. Works like a champ.

Computer fans are all over the place with wires - and it sounds like the fan you got is temperature controlled. Easy to do - you are talking about only 12v and very low amperage - just take the two wires you have power to and start trying combinations - only one combination will work.

However if I had to bet on it... yellow is positive and black is negative - just my guess though.

Good luck - feel free to PM me if you have any specific questions - as I said, I just did this myself


----------



## vim (Jun 29, 2011)

sayurasem said:


> btw, I have green, black, blue, yellow....


http://www.allpinouts.org/index.php/Motherboard_(CPU)_4_Pin_Fan

you'll be wanting the black and yellow wires :icon_wink


----------



## HD Blazingwolf (May 12, 2011)

redfishsc said:


> Agreed with the above, but I'll add two quick points.
> 
> Don't fret polarity. If you wire the fan backwards, it just blows backwards. No harm at all, just orient the fan to blow whatever way you want it.


this iis absurd.. do u understand dc? direct current there are very few things dc that i know of that can run backwards...
computer fans are not oone of them, if u wire it wrong dont fret. it just wont turn on

green black blue yellow wires indicate that it is probably a cpu fan for variable control. or its a fancy variable control anyways. most of the time tho, variable control that arent for cpus, run red and black for positive. black is most likely ur ground. and blue ur power


----------



## flip9 (Jun 16, 2011)

Case fan or CPU fan?










Pin 1 is always ground (usually black)
Pin 2 is 12v (yellow)
Pin 3 is fan speed sensor (green)
Pin 4 is fan controller (optional)

If your wiring it into USB, heres the pin out

4 wires:
-- Ground (black)
-- Data - (white)
-- Data + (green)
-- 5v (red)

12v fans will function on 5v, 7v and 12v. Feeding it 5v (USB power) is the slowest fan speed. If your plugging into a PSU (Molex) there are different ways of wiring it for different voltages.


----------



## redfishsc (Aug 29, 2010)

HD Blazingwolf said:


> this iis absurd.. do u understand dc? direct current there are very few things dc that i know of that can run backwards...
> computer fans are not oone of them, if u wire it wrong dont fret. it just wont turn on


I stand corrected on this, I just went and tested it, and they indeed didn't run backwards. Although there are two things I'd like to point out. 

1) I have an _amazing_ track record b/c I've totally ignored polarity on every DC fan I've ever wired up (about a dozen) and never once had a problem. 

2) Arrogance and insult are pitiful ways of correcting someone.


----------



## HD Blazingwolf (May 12, 2011)

yeah my bad, it was a bad morning. i didn't really mean to take it out on you


----------

