Had to replace an interface module on a honeywell mod. motor and when i tryed to adjust the Zero setting i can turn the pot. all the way and the motor will not move. Not sure if i am missing something, has anyone had this problem before. The instruction say turn the zero pot all the way clockwise and the span pot all the way conterclockwise. the send closing signal (0v) turn zero pot conter clockwise untill motor starts to move then turn it back untill it stops moving. I can turn it all the way conterclockwise and the motor does not budge. Motor test out find. Used a pot can control it all the way from closed to open with out a problem. If i turn the span pot all the way clockwise and then turn the zero pot. I can get the motor to move. Any chance the instruction are wrong?