Could be a number of things, but the first thing I'd do is lightly file the brass bars and springs on the left end of head to shine them up good. We've had them get gunky and not make good contact.
yes that is the n1cause after lock up and running wheat or other small grain, make sure the brass bar is in fact touching the springs and the feeler bar is not hung up.
check to make sure you have the head pluged in the right way, its possible to plug it backwards, the white wires must meet the white wires or it won"t lower in the auto mode.
