Molex modding

[samqweqwe]

hello,
i have too many fans and they are very loud and there was a site that said about molex cable and how to modd them. i know what the colours on the molex connector mean but i remember that the site was good at decribing how to mod them. unfortuanatly i have lost the URL for this site . I am wondering if anyone has come across it and could tell me the URL.

thanks in advance

 

[Ubrales]

I have heard of "Daisy chaining" Molex connectors attached to fans. Can you elaborate on what you are looking for when you say Molex modding?

 

[wiggbot]

I can give you a quick run down. Yellow is +12 volts, red is +5 volts, and black is ground.

By cutting and resoldering wires in different configurations, you can achieve different voltages. The possibilities are +12, +7, and +5 volts.

You'll notice that the fan normally connects to the yellow and one of the black ones, giving you 12 volts.

To get 5 volts, you need to cut the yellow and red wires, and then solder the red 5 volt wire to where the fan would normally get its 12 volt yellow wire.

To get 7 volts, you need to cut the black ground wire and the red 5 volt wire. Solder the red 5 volt wire to where the fan would normally get ground.

edit:
http://www.techpowerup.com/articles/other/137

Here's if you want to try to save pins. I find it too big of a pain and just solder. At the moment, all of my case fans are running at 7 volts.

 

[samqweqwe]

Wiggbot is talking about the mod that i want to do. instead of having it to stay at a certian value (ie 5 volts, 12volts), i would like to choose between 7 and 5v. this could be achieved with a double pole double throw toggle switch but i dont know how to set this up

 

[Ubrales]

Then do the mod and connect both modded as well as normal Molex tot he double trow switch. Then you can switch between the two voltages and use that as a speed control feature.

Why not just install a fan speed control?

http://www.newegg.com/Product/Product.aspx?Item=N82E16811999171 (many others at Newegg)

 

[samqweqwe]

I have already got one but it is not very good as it only has 3 speeds and on the lowest the fans are still loud. That is why i want do this so the fan controller can be a bit quieter as it goes through 2 controllers

 

[Ubrales]

I have already got one but it is not very good as it only has 3 speeds and on the lowest the fans are still loud. That is why i want do this so the fan controller can be a bit quieter as it goes through 2 controllers

The fan sound has nothing to do with the fan control; the only thing that matters is the fan RPMs!

if this is the case then look into replacing the loud fans with new quiet ones. Check the customer feedback before you buy new fans.

 

[samqweqwe]

reducing the voltage would make a smaller rpm therefore making it quieter.

 

[wiggbot]

http://imgur.com/6kq5UKh

This is what you're looking for.

One thing to keep in mind is the fact that some fans may not start at 5v, but be able to operate there. On the other hand, they should fire up at 7v. Thus, you could always power up the computer in 7v mode and switch over to 5v, or just check to see if all of your fans fire up at 5v.

 

[samqweqwe]

that wha i am trying to do but i am wondering if it should be 5v to 7v or 5v to 12v or 7v to 12v.

 

[wiggbot]

Depends on your case, the amount of fans, etc.

My case has a lot of fans. To be exact, 2 front and 1 side intake, and 2 top and 1 rear exhaust. I don't have to spin my fans very fast to get effective cooling. At the moment I'm running all of them at 7v. It is quiet enough that it doesn't bug me, and the temperature differences I was getting from running them at 12v is around 2 to 3 degrees. It isn't worth it to me to have it slightly cooler, yet sounding like a vacuum cleaner.

Basically, you should experiment. Run a test with your fans at 12v, 7v, and 5v. Do the same thing (ie prime95 for 20 minutes, etc) and see what differences you get. Then, make the decision with that knowledge. There isn't much sense for me to tell you exactly what you need because I don't know what the variables are.

If you are looking for something like a definitive answer, I'd say make the 7v/5v switch. If that isn't good enough in the future, it's only a few minutes work away from being a 12v/7v switch.