Clean the Pawl Magnet Core inside the Pawl Magnet Coil. This is a common problem with a 6850BJ (Advancer) Selector. It will hang up in one direction from residual and will soon not reset in either direction if not cleaned. Make sure your getting reset voltage to the coil. Do not Lower the resistor value in the reset circuit. If the reset coil is energized to strong the reset will swing to set and never release the stop lugs.
