adjust so as All three springs are in line vertically with no bars touching. Then with the header up, unlocked, all linkgages bottomed out, with the feeler fingers just touching all across, adjust the turn buckle so as to make the back bar pull the springs forward about a 1_4". When the header lowers it will go into a'dead' zone. At this sime you will not be able to raise the head with the l-m-h knob in the cab. The theory is the bar touches or comes away from contack with the top spring first - high- the middle - mid second - and the lower last -low. To check this operation, take the throat chain off, take the turn buckle loose and start the machine and use a pencil to move the plastic back and forth to simulate field movement. Check on low , med , high to insure proper operation. Many times it is a broke wire, inside the harness, right where the throat pivots that is the culprit for erratic operation. This can be diagnosed by checking for voltage at the module for feed back of current from the low mid high wires.