Added the rudder sensor to our wheelpilot ST4000+ but it doesn't show up on the display. There is power to the sensor from the AP head: red 5.6v, blue 3v and green .8v to the silver ground. Earlier 4000 heads had a calibration setting 8 to tell it the sensor is installed. The ST4000+ just says 14 after holding down the Standby button. And I've been told by Ray folks that this head needs no "introduction" to the sensor; it should just see it. Any help available on this? Thx.