Re-calibrating Compass on AutoPilot

[downtown]

Just had my linear feedback unit replaced on 92 Marlin.

AutoPilot working, but seems to have quite a different compass reading than GPS and compass.

Any ideas on how I re-calibrate? It is a Robertson AP-11.

 

[megabytes]

There are several steps which are a bit involved to explain here. The best bet is to go through the entire setup. The AP-11 manual is online at Simrad's website. The main changes you will need to make during the procedure are:

o calibrate the rudder
o swing the compass (slow circle to find magnetic deviations)
o calibrate the compass heading (I use GPS while moving in several directions to average out the best reading)
o zero the rudder (ensure the boat moves straight when the rudder feedback is at zero)