Someone may have asked this earlier but I am having trouble with the auto header. Had the tech out and said to replace the height selector knob in console. Not the problem. You can lower the header and move the height switch and the head will slowly pulsate and sporaticaly raise. You can turn the knob lower and it will stop and thats it. Turn it higher and it starts pulsating again. I have to manually lower it to the ground when its in auto. Any ideas? Thanks.