@dc42 said in Duet3D 6HC - FAN WS7040+Drive - wiring and configuration help:
If your original connection method didn't work then adding a 10K pullup resistor between OUT4_NEG (the pin that I think you are calling OUT4 in your post) and +5V from any IO_OUT connector should fix it. That would avoid having to use up the 5V_PWM pin.
I tried this solution and it also works as expected.
The only drawback is that when you first turn on the machine or restart Duet, the fan goes Max speed and it is really loud.
I will keep it using the OUT_9 5V PWM + OUT4_Tach as final solution.
Thanks for all the help and super quick response from all of you!