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Fan Controllers - Only 3-pin not 4-pin (Molex) ?

Last response: in Components
August 7, 2009 7:32:45 AM


I'm planning to buy a Fan Controller for controlling my 4 LED-fans (2x 80mm & 2x 120mm)...

The "problem" is (at least for the cheapest ones) most seem to include only 3-pin connectors for the fans. All my fans have Molex 4-pin male/female connectors. So do I have to buy for each fan some kind of "4-pin to 3-pin -adapters" and add my wire mess inside my modded window case?!

Few fans nowadays seem to use 3-pin connectors anymore...

For example, have looked this one:
August 7, 2009 7:43:28 AM

The "problem" is (at least for the cheapest ones) most seem to include only 3-pin connectors for the fans.

System fans require 3 pins (neg/pos/control), not two (neg/pos), in order for the speed to be monitored by a fan controller. Like this one.
August 7, 2009 7:56:09 AM

the 4th pin has to do with fan speed management, if memory serves, when you plug a 4 pin directly on a 3 pin the fan speed goes to max, which you then would be able to manage with your fan controler...

Just to be safe try google. :) 
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August 7, 2009 8:03:23 AM

A 4 pin molex supplies 12v power from the PSU. There is no built in 'controller' on a 12v four pin molex connector.
August 7, 2009 8:12:39 AM

If OP wants to use a fan 'controller' to 'control' the speed of system fans, the fans will have to be of the 3 pin variety (neg/pos/'control').
August 7, 2009 11:51:57 AM

Your fan controller is fine, most likely it is your fans that are cheap; I'm guessing they actually only run two wires to the Molex connector (ground and +12V), so they run at max speed all the time. You may wish to consider buying some new fans, and get some that have 3-pin connectors, or say they have both.
August 7, 2009 5:41:46 PM

Yeah, that's probably true :D ! But I don't want to buy new fans because just bought them :/ !

So, if I cut the 4-pin connectors from two wires of my fans and replace them with 3-pin connectors by soldering. That should do the thing, right?!