I bought a 3-way PWM splitter and run all fans in full speed.

[Zhenpeng]

I have a GA-Z170X-Gaming 3 motherboard. I need to install more fans on the case so I bought a 3-way PWM fan splitter. I put in 3 CoolerMaster Jetflo fans on the splitter and all 3 fans started to run at full speed. Looks like the motherboard doesn't have control over the 3 fans on the 3-way splitter, but at least I can see the speed of the fans...

 

[CircuitDaemon]

If you connect one at a time, does the motherboard control their speed? There's no big science behind it, either it works or it doesn't. You might have some setting in the bios that's disabling fan control, but I'd check one fan a a time first.

 

[photonboy]

1) Try one fan only to test without the MOLEX power connection

2) Use the motherboard fan control software

3) Once that works, add the other fans and power.

(I can't quite figure out how this works with the MOLEX adapter. That's a constant voltage. PWM works by pulsing the voltage on and off.)

Also, check the motherboard manual to see what the fan header max Amperage is. Each of the fans uses up to 0.4A so if you had at least 1.2A you can run all three without the MOLEX power connector. If 1A max you can support TWO fans without adapter (overloading can damage the motherboard).

 

[CircuitDaemon]

1) Try one fan only to test without the MOLEX power connection

2) Use the motherboard fan control software

3) Once that works, add the other fans and power.

(I can't quite figure out how this works with the MOLEX adapter. That's a constant voltage. PWM works by pulsing the voltage on and off.)

Also, check the motherboard manual to see what the fan header max Amperage is. Each of the fans uses up to 0.4A so if you had at least 1.2A you can run all three without the MOLEX power connector. If 1A max you can support TWO fans without adapter (overloading can damage the motherboard).

The molex side of the connector is only used for providing current to the fans, the extra fourth pin is what actually controls speed with a signal that's being sent from the motherboard. Even if you measure voltage from a PWM connector on the motherboard at a low speed setting, the +12 pin will always deliver 12 volts. Voltage only varies in fan controllers which are meant to be used on non PWM fans with only 2 or 3 pins. PWM doesn't adjust voltage from the connector but the fan itself does it.

 

[Zhenpeng]

1) Try one fan only to test without the MOLEX power connection

2) Use the motherboard fan control software

3) Once that works, add the other fans and power.

(I can't quite figure out how this works with the MOLEX adapter. That's a constant voltage. PWM works by pulsing the voltage on and off.)

Also, check the motherboard manual to see what the fan header max Amperage is. Each of the fans uses up to 0.4A so if you had at least 1.2A you can run all three without the MOLEX power connector. If 1A max you can support TWO fans without adapter (overloading can damage the motherboard).

The molex side of the connector is only used for providing current to the fans, the extra fourth pin is what actually controls speed with a signal that's being sent from the motherboard. Even if you measure voltage from a PWM connector on the motherboard at a low speed setting, the +12 pin will always deliver 12 volts. Voltage only varies in fan controllers which are meant to be used on non PWM fans with only 2 or 3 pins. PWM doesn't adjust voltage from the connector but the fan itself does it.

Firstly, I'm using Gigabyte App to control the speed on fans, it works perfect when I plug the PWM fans directly to the motherboard. But when I use a splitter it just ignores the control from the motehrboard and runs at full speed, like it's plugged to the PSU only, because if I remove the PWM female from the Motherbaord the fans would be still running at full speed.

 

[Zhenpeng]

Never mind guys, I fixxed it, I just switched the "yellow"(VCC or +12v) cable with the "darkblue"(speed control) cable. Why? Because my motherboard's pins are like this: