I have a 93 1020 flex head on a 90 1680. Last year I was combining soybeans and I couldn't seem to get the auto header height to work correct. I put the new potentiometer meter on. But the head wouldn't stay still. Even on flat ground the head wouldn't stay in one spot it was always moving up and down. I set the sensitivity knob. I turned it up until the head raised. That seems to work correct. but then combining I would turn the sensitivity knob all the way down to shut it off and the head would still be real sensitive. It seems like I will let my feeder house down and it will go down nice and easy until about the bottom and then it will drop. Any ideas would help.