# Need Help - 4 pin to 2 pin Fan



## mello_newf (Oct 2, 2013)

Hi everyone, 

Had the fan seize up on my XFX HD 6870 after only 3 months of use  

Hope someone can help me out and tell me what wires I need to attach to turn a 4 pin fan connector into a 2 pin fan connector.

I really don't care if it runs at 100% all the time just want to get it going.

Where im at.

I think the blue wire on the 4 pin is negative, the green is positive, yellow is tacho and black is PWM (I think). Should I attach the positive and negative to the 2 pin or should i attach the positive and something else? 

Thanks,
Appreciate any help


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## TRWOV (Oct 2, 2013)

Is the original a 2 pin fan?


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## mello_newf (Oct 2, 2013)

Yes and it has fan speed control so im confused how its achieving this with 2 wires?


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## TRWOV (Oct 2, 2013)

It uses voltage control. The yellow wire (12V) on the 4 pin fan must go to the red lead (12V)on the 2 pin connector. The black wire on both connectors is ground.

You might need to cut the wires from the old fan and solder them to the correspondent wires on the new fan. I suspect the pin shape isn't the same between the two connectors.


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## mello_newf (Oct 2, 2013)

Giving it a go now. Thanks for the help!


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## TRWOV (Oct 2, 2013)

Make sure the replacement fan has the same amperage as the old one, or a little lower. If much higher the card's VRM _might not_ be able to drive the fan if it was designed to only deal that much current to it.


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## mello_newf (Oct 2, 2013)

Both 12V with .5A so should be good. Hope they get along together haha


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## mello_newf (Oct 2, 2013)

So she is up and running. Stress test @100% GPU&CPU for 10min and wont go past 66C (been at that temp for 5 min)

Better temps than I was getting with stock fan when it was new!

If anyone is interested I used the fan out of a XFX 8800 GTS shroud I had kicking around. Fits just right and 2 out of the 3 fan mounts line up. 

Thanks again TRWOV


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## Ja.KooLit (Oct 2, 2013)

mello_newf said:


> Both 12V with .5A so should be good. Hope they get along together haha
> 
> http://s23.postimg.org/d7wv6dy3v/photo_1.jpg




first time i saw a nvidia radeon card


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## Mussels (Oct 2, 2013)

put some asus and gigabyte stickers on there too, call it frankencard.


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## mello_newf (Oct 2, 2013)

I actually like it a lot more now haha. When I pull it to replace it with a newer card on water ill give it some more stickers and keep it around for a tester or another build


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## thebluebumblebee (Oct 2, 2013)

XFX and Nvidia back together again!


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## ste2425 (Oct 2, 2013)

mello_newf said:


> Both 12V with .5A so should be good. Hope they get along together haha
> 
> http://s23.postimg.org/d7wv6dy3v/photo_1.jpg



I'm glad I read through this post now


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## n-force (Dec 15, 2016)

I looked for this issue up and i found this topic right away, tried the solution and it worked all ok. Why do i bump after all these years? Well there is not enough info here. Voltage control is not always yellow cable and no info given about speed control and sensors . 

I soldered voltage control(in my case it was red) to red line and all others to black line, now it works completely ok with speed control now at last available. However i have no idea what would happen if i did red on red and black on black, unfortunately i have no information about sensors.

Thanks to op and trwov for help.


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## FreedomEclipse (Dec 15, 2016)

New member... Check
First post.... Check 
4 year old necro-thread.... Check


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## glassjaw (Dec 6, 2017)

Hey! I need to resurrect this post 

I'm trying to fit 2pin fan into 4pin. I didn't quite understand if mello_newf did any soldering or not? If not, how to connect the smaller connector into gpu? Thanks


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## jboydgolfer (Dec 6, 2017)

often. it generally goes something like this

pin 1 is - and pin 2 is +. Black goes to pin 1 and red goes to pin 2. Pin 1 should be black


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## glassjaw (Dec 6, 2017)

So no need to cut the wires?


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## jboydgolfer (Dec 6, 2017)

glassjaw said:


> So no need to cut the wires?



well thats determined by what it is your trying to do. but generally in the times ive needed to do this, ive had to cut the wires that werent needed. they also make an adapter for this purpose

im unclear what your trying to do, but it seems liek your trying to plug a 2pin Fan into a 4pin HEader, if thats the case, you might be able to just plug it in, but you wont be able to control speed, etc....either way, i would recommend that thsi only be a very temporary fix, until a proper fan can be ordered that actually fits the header in question.


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## glassjaw (Dec 6, 2017)

Thanks, I'm trying exactly that. I don't have manual controls of the speed anyway... It spins as it wishes


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## jboydgolfer (Dec 6, 2017)

glassjaw said:


> Thanks, I'm trying exactly that. I don't have manual controls of the speed anyway... It spins as it wishes



I hope it works out for you

 One more thing, I really would like to stress the fact that you should get a proper replacement as soon as possible.... although nothing terrible would likely happen, it's in my opinion,  best to have suitable components for suitable applications, but if tou dont end up cutting anything, it should be fine


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