Auto tilt control on Iseki TF5

[Blue Thunder]

I bought an Iseki SIAL (TF5) and it has a litlle control panel for tilt on the 3pt hitch.
A toggle switch controls the tilt of the 3pt hitch. But I'm still figuring out the other knobs on the panel. One is a turning switch with three positions. In one position nothing seems to happen. The two other positions make th tilt cilinder go all the way up and it sounds like it keeps the valve open. The other one is a "potmeter" and seems to have no function at all. But I'm sure it does. Did anyone become wiser about this topic in?

Meantime I figured out that there is a electrical connector for using an auto tilt sensor. So next question is now which one would be usable?
I hope someone can give me at least some hint about this.

I found some interesting (but old) topics about auto tilt control but none with enough information to start with.

 

[Blue Thunder]

In the mean time I have be investigating the Sial more in detail and found a interesting little sensor in the area of the cardan.
Found out that a little rod is missing (see pictures) When I manipulate the sensor manually, the tilt is adjusted while I'm turning the sensor.
Now we are getting somewhere. Just have to make a rod that fits and we are working again.