Wpm421 Water Pump

Hello

I have the water pump wpm421 and try to control it with PMW. However, the pump works only with 12V and nothing below.
I also tried the suggestion of the VMA412 (this is the old version) but it does not help, see here: Vma412 Adapter doesn't exists? What now? - #3 by jhelbling
(Also tried with the "MotorDriver2 and 1803BK).

If I connect it directly to a 5V source (or anything in between), it works great. I just can’t control the speed with the Arduino.

Is the singal the Problem? Does it Somehow interween with the brushless DC Motor?