This is for adjusting the water flow from a hydraulic driven bean pump on a ditch witch directional drill. Currently the adjustment know does do anything. The drill is putting out way to much water and I need to tone it down. There is a three way switch for activating the solenoid to turn on water. Middle is off up is momentary on and down switches and stays but doesn't do anything. From looking at this diagram it looks like up directly grounds the solenoid giving 100% on and turning the switch to on goes through the reostat know which should give a pulse width ground to solenoid to slow it down? Just want to understand before I start trying to fix it. Thanks for reading.
I checked the wires at the adjuster knob and they were getting battery voltage instead 5v. I have a another machine for parts and swapped the "fluid controller" over. Getting 5v at knob now and system seems to be working for the first time since I bought the machine.
I'm looking at the schematic and that bottom right corner below the rheostat leaves a lot to be desired. It almost looks as though the fluid switch will ground the PWM driver or the bottom end of the rheo' . Glad you solved it, wish I could have helped.