Nah, fook dat - it disappears into a big bowl of spaghetti above the BSI and I can't trace it any further because my arms aren't long enough. I also managed to yank the brake light switch out

There's no orphaned connectors that I can see either. Game over I reckon. Maybe next year I'll have the dash to bits but just now it's too cold for any of that.
Oh, and I had the cover off that connector - pffff, EOBD anyone?
Cheers for the link anyway Dog'slife, lots of interesting stuff including a schematic of the com2000 - I might actually be able to come up with something useful for the chap with the dead window washers...