Hello all:
I've bought a PWM generator like this one:


And I want to connect it to 4x 12V Fans with PWM connector but I'm having some issues. Basically I'm connecting things this way:

But I'm always getting the fans to rotate at full speed with no control at all. Also tried to disconnect the GND that connects the PSU to the FAN HUB, and I was able to control the fan but they stop and start, the speed is not constant. I also notice that where I should have 12V constant I get oscillations. If I measure between IN+ and IN - I get 12V but if I measure FAN1 between VCC and GND I get the same oscillations that I get measuring between PWM and GND. Am I having some ground issues?
Thank you all for the help!
I've bought a PWM generator like this one:


And I want to connect it to 4x 12V Fans with PWM connector but I'm having some issues. Basically I'm connecting things this way:

But I'm always getting the fans to rotate at full speed with no control at all. Also tried to disconnect the GND that connects the PSU to the FAN HUB, and I was able to control the fan but they stop and start, the speed is not constant. I also notice that where I should have 12V constant I get oscillations. If I measure between IN+ and IN - I get 12V but if I measure FAN1 between VCC and GND I get the same oscillations that I get measuring between PWM and GND. Am I having some ground issues?
Thank you all for the help!