Rewiring Case Fans

[Indybird]

I have a NZXT Lexa which comes with 4 120mm fans that use Molex connectors for power. How do I rewire those to a three-pin connectors? I'd like to hook these up to my motherboard, for monitoring and controlling. I don't know a whole lot about wiring and voltage and that stuff.

Thanks,
Indybird

[Airbozo]

Not 100% on this, but since they only have the power wires there would be no way to monitor them. I had a similar issue with another case and just replaced the fans... (only 2 of them so it was not that expensive).

[Indybird]

Do they need to be monitored?

[Razors Edge]

Thermaltake.com there are fan controllers, fits in one of you're 5.25" drive bays, you can adjust speed and stuff.

[Airbozo]

Depends on the mobo. I have one MB that will shut down as soon as it powers on because it does not see a signal from the cpu fan, and it will also beep if it does not see signals from the PSfan or case fan (although I can turn off the ps and case fan monitoring in the bios).

[dgrmkrp]

usually, a 2 wire fan comes with a molex connector only.. if your fans have only molexes.. i'm sorry, no way you can monitor them.. you can think about/calculate a guessed rpm by the voltage your putting into them.. if you really want to monitor the rpm.. u need to change them.. as far as fans go, if you have 3 wires or more, you can monitor and even control the rpm (4th wire=PWM).. but there is no way to monitor a 2 wire fan, because there is no such circuitry in the fan hub.. but if u want to know, use a laser thingy car shops have to read the rpms on engines :)

[Razors Edge]

Or just buy new fans. There like 2 or 3 bucks on newegg.

[chedabob]

you could use a multimeter to find out which pins are the 12v and grounds, then just wire them to it. you wont be able to monitor them, but they will run. they will run at full speed, so id put a potentiometer on the 12v

[Airbozo]

Your mobo manual should tell you the pinout of the fan connectors...

[dgrmkrp]

...or:
from the psu side: yellow 12V, red 5V, black's are ground.. i run my fans on the 5v line now, for some peace and quiet..
on the fan side: red is + and black is... - :) yellow is for rpm... if there is yellow :)
usually, i don't use a mulktimeter becasue i'm carefull about the colors.. but it's safe and very handy to use one when you're dealing with silver wires or other exceptions.. ah, another rule of thumb i learned 10 years ago.. in the old days, when we put computers together, we always said red goes with red.. the ide cable has a red stripe on one end.. this would be aligned with the 5v from the psu.. they would be like ...||.................etc in a hdd or cd-rom :) so, you can tell the voltages from this simple rule, as a molex connector goes in only in one way (unless you're strong) :)