I have a 2008 850d that is new to me and that I’m restoring. I am stuck on an issue that I cant resolve on my own. The 4x4 switch is not activating the 4x4. Disconnected the plug where wires enter the front diff and tried putting 12 v directly and nothing. Am I missing something here ? Should I be doing something else to allow the device to show signs of life ? I noticed that my front diff differs from what is shown online at JD parts. I probably have an earlier version or something. I found my exact model front diff fitted on the 2008 620i. Thought I give you a try before I tear into this diff to see if I can diagnose the issue. Where is the fuse or relay located for the 4x4 actuator. What do these 2 wires that lead into the front diff connect to. My front diff does not have the actuator attached to the front diff housing like most that I see.