Hello Elektrodrive
First Happy New Year to you and for all good people on this forum.
How I know this model of truck and I was work on some of them steer is active on left unit of MP1514(I cant remember).This type of truck have Interface board on the right side(front side where is multipilot or solopilot for hydraulic).Problem on that board is bad stamp and brake on board.More one thing is important Jung have some strange solution that lives jumpers for some function so maybe you just dont have them.Please look board that I told you and tell me serial for future help.
Good luck mate
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.