Sign in with
Sign up | Sign in
Your question
Solved

Case fan with 3 pin female end

Last response: in Components
Share
April 26, 2012 3:29:17 PM

I have a case fan that has a 3 pin female cable. Where do I find an adapter cable to plug it directly into the daisy chain power supply? Most of the adapters I've seen they seem to have 2 pins (male end) to 4 pin molex, I tried that and it does not power my fan. I have a large fan, not the small ones. I guess I need something with 3 pins (male) not 2. Any suggestions?
a b ) Power supply
April 26, 2012 6:25:05 PM

Have you checked your motherboard, You motherboard should have Fan headers/ 3-4pin male fan pins. If not then you can get a 4 pin molex to 3 pin male
m
0
l
Related resources
a b ) Power supply
April 26, 2012 6:54:30 PM

the third pin allows the mobo to sense the fan speed, and so if you are connecting it to the psu directly it is not needed
m
0
l

Best solution

a b ) Power supply
April 27, 2012 2:03:58 AM

An adapter going from 4-pin Molex male to 2-pin fan male certainly should power your 3-pin fan. Make sure you plug the fan into the adapter's 2 pins correctly - there should be a plastic tongue and matching groove to allow them to fit together only one way. This connection puts Ground on Pin 1 (fan's Black wire) and +12 VDC on Pin 2 (fan's Red wire), and no connection to fan's Yellow wire on Pin 3. That Yellow is the speed pulse signal generated in the fan motor and sent back to the mobo for monitoring ONLY if you plug it into a mobo SYS_FAN port.
Share
April 27, 2012 3:30:41 AM

Rockdpm said:
Have you checked your motherboard, You motherboard should have Fan headers/ 3-4pin male fan pins. If not then you can get a 4 pin molex to 3 pin male


Yes, my mobo has 3-pin male fan pins (CHASSIS_Pwr). When I connect a smaller fan to it it works, but when I try the larger fan it won't start at all. I also tried connecting the larger fan to the PSU directly (daisy chain) using the 4 pin molex to 2 pin fan male adaptor and that did not work either. Is it possible I have a defective fan (the larger one) or my psu or mobo is not supplying enough power to the larger fan?

I noticed that the label for the smaller fan says 0.11 A. The label for the larger fan says 0.21 A. (Amps) It looks like the power requirements are different for both fans.
m
0
l
April 27, 2012 3:34:27 AM

Paperdoc said:
An adapter going from 4-pin Molex male to 2-pin fan male certainly should power your 3-pin fan. Make sure you plug the fan into the adapter's 2 pins correctly - there should be a plastic tongue and matching groove to allow them to fit together only one way. This connection puts Ground on Pin 1 (fan's Black wire) and +12 VDC on Pin 2 (fan's Red wire), and no connection to fan's Yellow wire on Pin 3. That Yellow is the speed pulse signal generated in the fan motor and sent back to the mobo for monitoring ONLY if you plug it into a mobo SYS_FAN port.


Yes, I've tried that and the fan won't work. Look at my reply to Rockdpm.
m
0
l
a b ) Power supply
April 27, 2012 4:40:41 PM

Both the mobo port and the Molex connector certainly can supply enough power for the larger fan that runs at 0.21 A - starting current will be much higher for a couple seconds. If it won't work when connected to either power source, it must be faulty. And to confirm, you've already proven that he power sources are OK by using the smaller fan to test.
m
0
l
May 7, 2012 3:14:03 PM

Best answer selected by jlores78.
m
0
l
!