"Lionheart" has a B&G Pilot autopilot with electro-hydraulic (the blue one,
RAM-T1-12V) ram directly on her rudder bellcrank. The rudder position
sensor to feedback to the computer box is the Linear Feedback Unit strapped
to the side of the ram cylinder.

During the preflight checkout for our recent trip, I couldn't get the Pilot
display to show the proper position of the rudder when I turned the wheel
over by hand, stop to stop. After unloading the captain's stuff from over
the rudder post, I noted the strap holding the linear actuator (crappy hose
clamps) to the ram cylinder was loose and the mounting block that holds the
linear feedback unit off the ram had moved. Simply tightening it back
won't fix it. You need to do a cal on the linear feedback unit that's NOT
in the manual or commissioning manual. A call to B&G's NEW Clearwater
number (727) 540 0229 got great response and instructions I'd like to pass
on here....

To calibrate the linear feedback unit, tighten it back on so it can't move
with the grease fitting so you can lube it. Make sure it will not be
pulled too far out or in when the rudder moves to its stops, which will
destroy it of course. Set the rudder so the linear feedback unit is fully
compressed (in). Loosen the locknut holding the end of the moving actuator
rod to the rudder drive unit. We're going to be TURNING this linear
feedback unit actuator rod after we get its wires loose from the Advanced
Control Unit (ACU). Isn't this fun?

Open the ACU (the computer box) and note the colors of the wires coming
from the linear feedback unit do NOT match the colors marked on the holes
they go into. (Red wire to Red, Black wire to Blue, White wire to Green,
shield wire to grey on the end even though it doesn't say.) After making a
little drawing so you can get them back, remove them all and pull the cable
out where you can get to the wires. Go get your digital multimeter.

Connect one of the DMM probes to white, the other to black. Set the DMM to
read OHMS. If it doesn't autorange, we're going to be looking for 250-350
ohms so set the appropriate range manually. Now, while someone at the
linear feedback unit ROTATES (not plunges) the rod of it around on its
loosened nut, you read the meter and stop them when the resistance between
the black and white wires reads 250-350 ohms....which is 300 ohms there in
the middle. Tighten down the locking nuts so the linear feedback unit rod
cannot rotate on its own as it slides in and out. Of course, if the body
of the LFU rotates, like ours did, that screws up this setting, also.

Reinstall the wiring from the linear feedback unit into the Advanced
Control Unit, making sure the right wires are in the right holes. This
completes the MECHANICAL calibration of the linear feedback unit.

Follow the instructions in the Commissioning Manual and recommission your
Pilot as to Rudder End Stops, Rudder Midship and let the computer run the
Rudder Hard Over Time test it does. Make sure you step through ALL THE
SETUP FOR ALONGSIDE COMMISSIONING even if you don't change other settings
as it won't store the new settings if you don't on ours.

Oh, it's SO nice to see that rudder position display now running perfectly,
again. "The Ghost", as we call the totally silent B&G Pilot on Lionheart,
is back in action.....er, ah, even if the crew blew out the headsail in
heavy seas/winds...(c; The old headsail finally bit the dust, her
stitching just pulled apart. The cautious engineer (me) talked the captain
into turning us back to port as there were just the two of us handling the
41' ketch in heavy seas....in no position to change the headsail at sea in
these waves!....We motored safely home...

I printed out these instructions and pasted them into the commissioning
manual on Lionheart for future reference. It'll come loose again...you
just know it....