Thought I would share my findings. Had an 2015 merc actros unit in, with the left hand indicator/wiper stalk and rear axle level controls inop. Using star computer had fault codes for LIN circuit short to everything lol. Using the wiring diagrams to locate all the plugs between the steering column and that SSAM unit in the left kick panel. All the wiring looking ok and passing continuity test, even the trapped wire between the dash. Moving on to the axle lift control pulling the floor carpet/mat up found a corroded plug for it. Cause of the corrosion was the stored Adblue container in the storage hole behind the main cab, had fallen over and then leaked under the floor. Plug and pins all cleaned up, now all back a functioning. Happy customer. Lol