For the longest time, I could not calibrate my autopilot, (you know where you go out in the harbor and do 360s for three times).
Anyway, autopilot didn't work cause the fluxgate compass was not calibrated. I traced the wires and the installer of the autopilot had run the wires under a motor mount and the cable had been crushed. They neatly put a short piece of black tape on the damage to disguise it.
So. I need to shorten the cable to remove the splice. To accomplish this I relocated the compass to the the CL of the boat under the aft berth and reconnected the wires.
After the connection was remade, the autopilot recalibrated on the first spin in the harbor. Success!