[quote=“Val, post:26, topic:4468”]
Yes I have a steer ready tractor 
The steer diagram in zip file looks to be quite the same than the diagram that I use. 
So I just need to delete the wire from dump valve to the SRD-05VDC-SL-C (the arduino high level trigger if I well understand).
The Arduino type has optocoupler which protects the Nano better.
Look further down about wires
I also should connect the signal wire from pressure sensor to A0. I think that I always would need to install a potentiometer and a resistor ?
If you want to use the Remote input (the O in) like in the schematics you posted above then yes.
But if you use A0 on PCB going direct to Nano, and use the settings (see page 14 and 15 in the new Manual.pdf) then no.
I had a new close look at the schematic you put above, and you have put wire numbers correct.
The only wire to remove is the green (same color as your ? mark) the line between relay and pressure sensor. (I don´t know why it is there, but maybe a different pressure sensor with 4 pins)
The only wires you probably should not use are 3100 and 3140, because the tractor already feeds WAS with 5V and GND.
I just made a Y connection between the two connectors at front of tractor for 3120 (WAS signal). This way you still have signal to control the (automatic) differential lock on tractor.
Notice: The wire 3168 comes from tractor ecu to x710 (tractor ecu probably controls by CAN messages between original GPS and tractor ecu, and gives 12 V to 3168 when everything is OK).
That is why I connect my own wire from arduino relay to wire 3168 at x710 .