Wiring Diagram or HELP

I have a 1988 320i Convertable bought 3 months ago

It has the following problem
Needs the Coil connected to battery to run (via fuzebox)
Washers do not work (Motor OK) Washers OK
Electric Mirrors do not work (Unless connected directly)
Eco meter and Tach do not work
HeatedSeatin not working (but did when I bought it!!!)
Cruise control not working but did a week ago
Electric Arial not working
Central Locking not working (Not thought to be conected to above problems cause its a different circuit

I have removed to Imobiliser

If I connect a new (Green) wire from the ignition switch to the Engine/Firewall connector the ignition and the Mirrors work !!!

So some where the Green wire seems to be loosing voltage (About 10 volts show). There are two wire that are green in the fuse box. I goes into the main block on the fuze box - the other goes to the forementioned connector on the fire wall

Any ideas HELP HELP HELP

I doent think its the Ignition Switch It certainly could be the fuze box as I have low voltage on a lot of the Fuzes!!!

Anybody go a wiring diagram - I am in the UK

I have ordered a Bentley Manual
I have a Haynes Manual(useless wiring diagram)

Try to remove fusebox and check plug connections underneath,possibly a plug has burnt out one of the terminals or is loose and causing a volt drop.