Coupling coupling switch

When upgrading my omi with cruise control I somehow can’t get any further. The cruise control works, only the function of the clutch switch is not given. The voltage arrives at the switch, it also switches very well, but the black-brown cable obviously has no connection with the blue-black cable, which arrives at the cruise control. According to the schematic this should be done directly. So far I also found no possibility of this cable at distinctive St The cable from the cruise control box goes through the spray wall, that is, behind the passenger airbag. If this cable is perhaps passed near the radio, I could measure it. And if I just want to pull a new cable, I’m practically faced with the same problem: somehow I have to expand the whole dashboard, too. to move it meaningfully…