Wiring diagrams for BMW
 

I came upon the two sites from another forum and figured that it might be helpful for ti owners too. Not sure if you have it already but if not then you can use it for your troubleshooting or next engine swap.

http://wedophones.com/BMWManualsLead.htm

http://spaghetticoder.org/bmw/wds/ (newer BMW)

The most relevant of those have been in our Files section for a while. That might even be where I found them.