[Chuck v]

Larry,


The step motor is similar to an electric window on a car...it senses stall current to know when it is at the end of its travel. If your step mechanism is binding or needs lubrication, the motor will stop short of full extension/retraction. Check for anything that is bent or rubbing as you watch it move in and out (and don't get anything pinched as you are down there...)


It could also be a loose/intermittent electrical connection, but more likely the above.


Chuck