Help with molex pins

[xRaidiant]

Hi I'm a first time pc builder and am a bit confused with these molex pins I received when I bought two 140mm fans off Newegg. So I receive a molex that has these pointy things on one and one with holes per fan. Do I connect the molex connectors of each fan to each other or the power supply...or the do I connect the fans to the motherboard? I tried connecting it to the power supply and after a struggle got the connectors and pins to connect and turned on the power supply to test the fans. The fans didn't start spinning so I'm wondering if I'm doings something wrong. Please help.

 

[Math Geek]

i think i know what you are saying but can you post a pic? would help me visualize what you have in front of you.

normally you get a molex to 3/4 pin adapter which is what i think you are asking about. but i'm not sure.

 

[Paperdoc]

I suspect what you have on each fan is a cable with two connectors on the end. One is a male (with pins inside a shroud) Molex that you can plug into a female 4-pin Molex power output connector from the PSU. The other is its female counterpart that looks a lot like the one coming from the PSU (but maybe missing the wires to two holes). The reason for that is that the female part of that connector pair simply "replaces" the female connector from the PSU that you "used up" by plugging in the first fan. So now you have a place to plug in your next fan WITHOUT "using up" a second PSU output connector. So you could plug several such fans in a series of stacked connectors, all into ONE output from the PSU. At the end of the line (the last fan) you will have one unused female connector to leave unused.

 

[xRaidiant]

i think i know what you are saying but can you post a pic? would help me visualize what you have in front of you.

normally you get a molex to 3/4 pin adapter which is what i think you are asking about. but i'm not sure.

Here is a picture. Where do I connect these molex pins to?

 

[Math Geek]

you forgot the link to the pic

 

[xRaidiant]

you forgot the link to the pic

How do I post a picture? I'm on mobile

 

[Math Geek]

go here http://imgur.com/ and upload the pics,. then share the link they give you here.

 

[xRaidiant]

go here http://imgur.com/ and upload the pics,. then share the link they give you here.

https://i.imgur.com/0iCDJIL.jpg

 

[xRaidiant]

go here http://imgur.com/ and upload the pics,. then share the link they give you here.

https://i.imgur.com/UpxT1mf.jpg

 

[Math Geek]

that's what i was thinking you had. paperdoc was right on with his description. the molex part is simply an input and output for the molex connections. if you only have 1 fan, then you're left with a females molex to plug something else into like an old hdd or something. otherwise leave it empty and tucked away. if you have more fans, then daisy chain the next one into the female output of the first one and so on until all are accounted for. then tuck it all away. plugged in this way, the motherboard won't control them so they will run 100% all the time unless you have a way to adjust them manually. some cases come with fan controls to adjust these fans. others just let em run 100%.

plug your white male end from the fan into the black female piece from the psu and then the fan to the 3 pin connection like the pic shows you already have. then plug then next fan into the white female from the first fan connection and so on.

 

[Paperdoc]

All that is right. But I noticed another detail in your first pic that you did not mention. It appears that the fan itself has three wires (Black / Red / Yellow) that end in a female (with 3 holes) standard 3-pin fan connector. THEN you have plugged that into the mating male connector that is part of the adapter system you described with two Molex connectors on it. Is that right? The fans themselves have 3-pin fan connectors, and thet came with separate adapters with Molex on them?

Well, you can use the adapters to connect them to your PSU as described above. BUT you also have the option of connecting them WITHOUT the adapters to mobo fan headers. If you do that, they will have their speeds automatically controlled by the mobo, instead of running full speed all the time. Because they are 3-pin fans, there is one detail that needs to be checked and maybe adjusted regarding your mobo. So, post back here exactly what maker and model number of mobo you have. We can look up its manual and advise your best option.

 

[xRaidiant]

All that is right. But I noticed another detail in your first pic that you did not mention. It appears that the fan itself has three wires (Black / Red / Yellow) that end in a female (with 3 holes) standard 3-pin fan connector. THEN you have plugged that into the mating male connector that is part of the adapter system you described with two Molex connectors on it. Is that right? The fans themselves have 3-pin fan connectors, and thet came with separate adapters with Molex on them?

Well, you can use the adapters to connect them to your PSU as described above. BUT you also have the option of connecting them WITHOUT the adapters to mobo fan headers. If you do that, they will have their speeds automatically controlled by the mobo, instead of running full speed all the time. Because they are 3-pin fans, there is one detail that needs to be checked and maybe adjusted regarding your mobo. So, post back here exactly what maker and model number of mobo you have. We can look up its manual and advise your best option.

https://imgur.com/a/pkf3P This is how it looks like without the molex adapter. Could I plug this directly into the mother board?
https://imgur.com/a/1VwR7 These are the two sets of female and male adapaters. So I connect the male to the PSU molex adaper and connect the other fans male to the female of the molex adapater that's connected to the PSU right? Thanks for the help

 

[Scottray]

Yes - you should plug the case fans into the case fan headers on the mobo. Note that the mobo's case fan headers can be 3 or 4 pin, depending on your mobo. If it's a 4 pin fan header, you can plug a 3 pin fan on to it. The header is built to accommodate both types. There's a "click" connector on the header and on the fan plug. It only fits on one way.

 

[Paperdoc]

Yes, you can connect those to any mobo fan header. They are "standard" 3-pin fan female connectors and will fit both 4-pin and 4-pin mobo SYS_FAN or CHA_FAN headers. However, some mobo fan header cannot control the speed of 3-pin fans. That is why I asked for details of your mobo. Then I can tell you if it can be done, and how to configure if needed.

 

[xRaidiant]

My motherboard is the MSI Z270 A-PRO can it control 3 pin fan headers?

 

[Paperdoc]

Yes, your mobo can be configured to power AND control your fans. It has four SYS_FANn headers for case ventilation fans, each with 4 pins. You CAN plug either 3-pin or 4-pin fans into them. So if you have four case fans or less, you can plug each of them into its own header and need no other accessories. You do not need those adapters for Molex connections.

After you plug those fans in and get your system able to start up, you need to make one configuration change in BIOS Set for EACH of the four SYS_FAN headers. See your manual, p. 36, for how to start. VERY shortly after you turn on there will be a message (usually at screen bottom) to press "Del" to enter BIOS Setup. I advise don't not just press and release - the system may not happen to see it when you press. Hold the "Del" key down until the opening screen of BIOS Setup shows, probably in EZ Mode (p. 38). At the bottom left, click on "Hardware Monitor". See p. 60.

For EACH of the four SYS_FAN units, click on its selector at top and then choose "DC" mode on the left. After setting all this way, exit from here and be sure to SAVE and EXIT. This will save your settings and reboot the machine. Setting things this way will make all of the SYS_FAN headers use DC Mode and control the speeds of your case 3-pin fans.