[SOLVED] Some questions about molex fans.

Jul 19, 2019
3
0
10
So hello there!
I’m going to build a pc for the first time ever in a few days, and I had some questions about fans.
I have ordered a case that comes with 3 preinstalled fans (1x 3-pin and 2x molex) , and I still have not found an answer for where to plug the molex fans. Is it possible to plug them in the motherboard? Do they plug straight into my PSU? The 3-pin fan is pretty obvious, that is going to go straight into mobo. I would really appreciate any help on this, because i’d like to utilize all fans and don’t want to screw up.

Motherboard - ASRock B450m Pro4
PSU - SilverStone SST-ST60F-ESB v 2.1

Hopefully any of you guys can help me!
 
Solution
4-pin molex are intended to be plugged into the power supply, yes.

This will run them at 12V, full speed, as long as the computer is on.

If they are too loud, you can swap the pins so that you use 5V as the negative, this will give the fans 7V+ and they will run roughly half speed.

4-pin Molex is 12+, GND, GND, 5V+ , Typically Yellow, Black, Black, Red. Pins can be removed by pressing in the tabs that prevent the pin from going backwards. This can be done with a small screwdriver or pin while applying pressure to the wire. (If you don't have the appropriate pin tool (which is a round tube essentially)

If you re-wired them you could plug them into a motherboard fan header. 3-pin fans are just 12+, GND, and a Sense wire for the RPM.

Eximo

Titan
Ambassador
4-pin molex are intended to be plugged into the power supply, yes.

This will run them at 12V, full speed, as long as the computer is on.

If they are too loud, you can swap the pins so that you use 5V as the negative, this will give the fans 7V+ and they will run roughly half speed.

4-pin Molex is 12+, GND, GND, 5V+ , Typically Yellow, Black, Black, Red. Pins can be removed by pressing in the tabs that prevent the pin from going backwards. This can be done with a small screwdriver or pin while applying pressure to the wire. (If you don't have the appropriate pin tool (which is a round tube essentially)

If you re-wired them you could plug them into a motherboard fan header. 3-pin fans are just 12+, GND, and a Sense wire for the RPM.
 
  • Like
Reactions: blurrijs
Solution
Jul 19, 2019
3
0
10
4-pin molex are intended to be plugged into the power supply, yes.

This will run them at 12V, full speed, as long as the computer is on.

If they are too loud, you can swap the pins so that you use 5V as the negative, this will give the fans 7V+ and they will run roughly half speed.

4-pin Molex is 12+, GND, GND, 5V+ , Typically Yellow, Black, Black, Red. Pins can be removed by pressing in the tabs that prevent the pin from going backwards. This can be done with a small screwdriver or pin while applying pressure to the wire. (If you don't have the appropriate pin tool (which is a round tube essentially)

If you re-wired them you could plug them into a motherboard fan header. 3-pin fans are just 12+, GND, and a Sense wire for the RPM.

I really appreciate your feedback! So if I don’t want to mess around and i’m happy that the fans run all the time, I should be able to just plug them into my PSU and it should work?