BMW: Speedometer signal retraction, bmw e30, wiring diagrams

Question
Hi Josh,
I am restoring a BMW E30 1989. I need to supply speedometer signal to my navigation system, and I would like to pick it off the harness which goes into the dashboard. Can you tell me which wire of which plug (left or right) supplies this signal?

Answer
Axel,
 You will have to look at wiring diagrams to decide what you need.  Unfortunately I dont know this off the top of my head.
 You can look on www.realoem.com for help.  I also suggest picking up a Bentley manual for reference.

 Good luck,
 Josh