How can I use a 3pin fan connector splitter (1-->3 splitt) that has only 2 pins?

Jon-Abraham

Prominent
Apr 11, 2017
11
0
510
Hi,
I've got a problem: My MOBO (Asus P8P67) has 2x 3pin connectors and 2x 4pin connectors. My CPU (NEPTON 240 M) takes two 4pin connectors (pump + 2x120 mm fans in a dual splitter). Then I am left with two 3pin connectors which optimally shall serve my case fans: 2x120mm (3pin) fans and 1x140mm (3pin) fan.

Simple logic says I am in short of one 3pin connector, then I stumbled over a fan connector splitter-cable - think it is OLD, and came with my MOBO. It has 1 head (that goes in the MOBO 3pin connector) and 3x 3pin connector/plugs (where the fan cable are connected).

My initial plan was to connect my 2x120mm case fans to the splitter, and then use only one connector on the MOBO, but then I also read something about beeing careful with these splitters... Another thing that made me uncertain was that both the 1 head and the 3 connectors of the splitter only had 2 pins (not 3pins.. :S). What is the consequence of that? And what should I do to solve the problem of having one 3pin connector short on my MOBO/for my setup?

PS!
Some technical specs for the fans: the two 120 mm fans says max input current 0,18 A. My 140mm says 0,20 A. I also read some place in the MOBO's manual that a connector supports 1 A output to the fans. Doesnt this mean that I can, practically speaking, do all my fans on that splitter? Just on one 3 pin connector? This is relevant cause I am thinking of upgrading to even one more 120mm fan in front (3x120mm in total) if it is possible to do so by the specs mentioned above.

Can anyone with more knowledge to this aid in making a sound desicion? Or any other solution?

I uploaded a picture of the splitter on youtube (se link):
https://youtu.be/_X41D7PZ6nM
 
Manual says about 1 A limit only for CPU fan. Other headers does not have any specification (but it is quite safe to assume it is similar).
You can safely use that splitter, most likely even with all 3 fans connected. I would make a test first to see if all 3 fans work properly. But you do not have to: note that there's another fan header labeled PWR_FAN. You could connect normal fan there, but it would not be controlled by BIOS.
 

Jon-Abraham

Prominent
Apr 11, 2017
11
0
510


What is the worst that could happen? And also, will i have control over 3pin fans when splitter only has 2 pins? I guess they are power and ground, wont it just run at max then?
 
Worst scenario - fried mobo. But most likely, they would just not start.
Control - they are voltage controlled, so 2 pins *could* be enough. But can't tell for sure - trying if it works (even if only with one fan connected via splitter) is your best shot. If control would not work, then yes they would run at max speed all time.