Question Fans in case are molex connectors

Oct 6, 2020
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My new cases fans only have molex 4 pins and I don’t want them to be on full blast 24/7 I need something like an adapter so I can control the speed with the motherboard
 
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ScrewySqrl

Champion
Moderator
those usually can't be controlled by software. you can get something like this to slow the fans down:

something similar with a dial to control the resistance level would let you manually set your speed
 

Lutfij

Titan
Moderator
Make and model of the case? If you're unsure, add a picture of the fans and their connectors end.

If the only method to power the fans is via the 4pin molex, then there's nothing possible outside of swapping the fans out for ones that connect to the motherboard.
 
Oct 6, 2020
24
0
10
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those usually can't be controlled by software. you can get something like this to slow the fans down:

something similar with a dial to control the resistance level would let you manually set your speed
I’m looking for something to be able to plug it into the motherboard though, I’ve seen the adapters that go from 4pin fan mobo connector (which can control speed) to multiple 3pin fan connectors, could I then get a molex adapter and use that on them to control it?
 

Paperdoc

Glorious
Ambassador
Wrong info above. You CAN connect those fans to a mobo header AND control their speed IF you set the header to use the older Voltage Control Mode (aka DC Mode), and not PWM Mode. Since the fans you have are supplied only with a Molex connector, I am sure they can NOT use PWM Mode. All you need is adapters for them, as you expect. Try this

https://www.amazon.com/3pin-power-4pin-molex-adapter/dp/B000H25PBK/ref=sr_1_36?dchild=1&keywords=computer+fan+adapter+to+Molex&qid=1601993021&sr=8-36

This adapter has a standard 3-pin female fan connector on one end to plug into any mobo header, and a standard 4-pin female Molex on the other end to connect to your fan's cable. It has contacts for only the +VDC and Ground lines, since that's all the fan can use. You will NOT "see" and fan speed in BIOS Setup or anywhere because such a fan normally does not have a speed signal output line.
 

Paperdoc

Glorious
Ambassador
OK, that changes things considerably. Your first post says each fan has ONE connector on a cable, and it is a 4-pin Molex. First, are you sure that all 4 pins of each connector are in use, with 4 wires going from connector to fan housing? I ask because most fan motors use 12 VDC, whereas many LED lighting systems use 5 VDC. A standard 4-pin Molex output provides both to those supplied on separate lines. The website says clearly that these fans with lights are NOT standard in any way, and the light displays are controlled totally by circuits built into the fans. So I would assume that you MUST provide to each fan the power normally available from a PSU 4-pin Molex output. If you were to use the adapters you requested (and I linked above) to provide a less-that-12 VDC supply on the 12 VDC lines of the connector, I have no idea what that would do to the LIGHTS in the fans.
 

madmatt30

Titan
Ambassador
OK, that changes things considerably. Your first post says each fan has ONE connector on a cable, and it is a 4-pin Molex. First, are you sure that all 4 pins of each connector are in use, with 4 wires going from connector to fan housing? I ask because most fan motors use 12 VDC, whereas many LED lighting systems use 5 VDC. A standard 4-pin Molex output provides both to those supplied on separate lines. The website says clearly that these fans with lights are NOT standard in any way, and the light displays are controlled totally by circuits built into the fans. So I would assume that you MUST provide to each fan the power normally available from a PSU 4-pin Molex output. If you were to use the adapters you requested (and I linked above) to provide a less-that-12 VDC supply on the 12 VDC lines of the connector, I have no idea what that would do to the LIGHTS in the fans.

Dropping to 7v would halve the brightness, any less and the rgbs wouldn't work at all.
 

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