Rick. The ST6000 comes in two versions. ST6000 and ST6000 Plus. These units have different calibrations procedures.
These AP's are made up of: a display, a computer, the motor drive system, a transducer to identify the rudder position, and your boats steering linkage.
Impossible to guess from the info as to which module is a problem. Here are 2 tests to help identify (at least the electrical side) which of your modules may be at issue.
Checking the Course Computer
It may be that the course computer is not outputting enough or any voltage out of the Motor terminals. To see if the course computer is the cause. if you remove the motor connections out of the course computer:
- and place a Multimeter in the wires place and then press Auto and then make a +30 course change
- You should see voltage increase
- Make a -30 course change and again you should see a change in the voltage but the polarity would be reversed
Also place your Multimeter on the clutch terminals and check that there is a 12v output when in Auto.
Checking the Rudder Reference Unit
The rudder reference transducer is the device that measures the travel of the rudder. The course computer watches the rudder reference transducer to see that the drive system is actually turning the rudder. Running the rudder reference transducer beyond the range of the pilot's electronic or boat's mechanical rudder stops, or a total failure of the rudder reference transducer will prevent the computer from seeing any rudder motion. If it sees no change in rudder angle after commanding the drive to turn, it assumes the drive is not responding to commands. To test the Rudder reference do the following:
- Looking at your display watch the rudder bar indicator and move the rudder. Does it move as it should?
- Does the rudder indicator wobble/move not as it should? If it does it indicates that the rudder reference unit is malfunctioning.
- Disconnect from the course computer and then Using a Multimeter cheeck the following,
- Cable colour ---- Arm position ----- Resistance
- Green/Red ---- Any position ----- 5k ohm +/- 5%
- Blue/Green ----- Anti clockwise stop ---- 1.66k ohm +/- 10%
- Blue/Green ---- Clockwise stop ----- 3.3k ohm +/- 10%
Should a test fail then that unit will need to be looked at by a Raymarine service agent. Please make sure that you carry out all the above checks.