The crosswind thought is wrong, there is no such thing as a crosswind in-air. There is just an airmass and an airplane moving relative to that airmass. Wind only exists relative to the earth's surface.
Make sure to follow Avidyne's voltage requirements, they exist for a reason. Getting your S-TEC servos fixed the official way will require them to be sent to Texas with a big cheque in the box. I recommend seeing that one avionics company in Bavaria, they have means...
If you have the details of the servo, it should be easy to bench test it. Probably it is just a dumb motor+gearbox, and maybe a tachometer whose output goes back to the AP computer
I am sure that a constant strong crosswind DOES create a greater load on the load servo
Not in this universe 
Seriously, as Achim says, a plane knows nothing about any (steady state) wind. It flies relative to still air. "Wind" is just a motion of the air over the ground underneath.
Think of a boat on a river, in thick fog so you can't see the riverbank. The boat (and anybody in it) thinks the water around it is stationary.
If an avionics shop said that crosswind affects the roll servo voltage, they should be shot.
Even if they were right, the application of any significant voltage to a roll servo will eventually drive the ailerons to the stops, and then crosswind will be the least of your problems.
I think that's wrong. In this case when the aircraft has to follow a certain groundtrack with, of course does the autopilot have to work more than without wind. (Same as rudder pressure necessary to keep aircraft on centerline during aproach).
("with" gpss), sorry
The only thing that would be correct is that if you don't care about the ground track and fly a circle or other maneuver it is all the same for the airplane because it flies in a movoing airmass package. I explain that differently though.
In the very moment you want to fly a prescribed ground track the WIND DOES MATTER. To make the airplane stay on the ground track the ailerons (because we have no autopilot that drives the rudder) DOES have to fight the crosswind constantly, and yes, the wind does create an additional load on the servo.
Just like the crosswind on final creates a load on your muscles.
Who wants to get shot first? :-)
If there is crosswind, you are just flying towards a different spot, and if you got it right, by the time you would have reached that spot, the wind will have carried you to the spot where you actually wanted to be.
As far as the plane is concerned, it is flying in still air. In steady state flight, the autopilot knows absolutely nothing about crosswind.
Just like the crosswind on final creates a load on your muscles.
Only if you fly a skewed final approach. If you fly the "crabbed" approach, you just fly a different heading, and your wings are still level.
Same as rudder pressure necessary to keep aircraft on centerline during aproach
I think you must be flying final approaches with crossed controls. It's OK; some people do that. But it's not relevant to the "frame of reference" discussion.
Back to the servos - if I can get some data, even the servo wiring diagram for the DFC90, that would be useful.
That is not correct, Peter. You can prove that to yourself the next time you want to keep the centerline on approach when you have a crosswind. I
S there a load on the muscle if you use the rudder to keep the plane on track? I think you are mixing up some things here, sorry.
To FLY to that other spot you have to stear. And if you let go (the rudder on final for example) the wind will carry you somewhere else.
Peter, if you fly a CRABBED approach you have to press the rudder, all the time (at least I always have to :-)). Which means there is a load on the muscle in your leg,... or on the servo
And that has NOTHING to do with crossed controls.
I have neen writing about this stuff professionally for 20 years now, and although I make stupid mistakes every now and then (and maybe more often than I should) - i am very sure about this.
The difference is that you want to stay on a ground track. What YOU say is only right for flying a heading. You turn the airplane to another point and since it is flying in an airmass it does not know about the wind
I will try to find the servo in the maintenance manual, THANK YOU for trying to help!
