Hello - I'm tracing a rear window defroster fault. I've narrowed it down in the cable between the rear power module connector X11012 and the connector to the glass X379. I have a good resistance in the defroster element, and a good ground. The relay I01061 functions and I have 12V on pin 21 of X11012 on the rear fuse holder. I'm trying to figure out what component Z1 is - can't find any information out online, and it's not in the Bentley manual. I tried signing up for BMW NA TIS online - but for some reason I can't get the registration to work. I'll wait until Monday and then call their help desk. Does anyone have any ideas? I've already replaced all the tailgate hinge wiring with the Sencom version a few years ago, but will check under the rear roof speaker anyway to see if I can find any broken wires.

 

I don't know what it is but I do know it's in the rear roof.

 

Sean - much appreciated, thanks. That module is mounted to the metal structure, just above the headliner. It's definitely my problem - some melting went on here.

 

I dropped the headliner to get access to the module. I think it might be an RF filter to reduce interference with the antennas in the back glass, so I just spliced Z1 out of the circuit. Time to test and reassemble.