Classic Audi - audi coupe gt5 1921wn schematics wanted please

went through a fair bit of water the other night, not too deep but some big puddles on the road. Went out again a bit later and she just went dead on me, no cough or splutter, just no power dash lights on no warning. Tried to start her again with no luck, left her for about ten mins then she started.
Next morning she started fine, warmed her up then drove to work then she died again after about 4miles (exactly the same with no warning). tried her a couple of times then took the dizzy cap off gave the rotor arm a quick scuff and put her back together.
tried a few times and finally got her going.
I took her to the local garage for a quick once over and when i went back to pick her up they had the fuse box out, theyd lost power to windows wipers and lights:eek::eek:
they then spent another morning putting her back to how she was when i took her in.
theyve put a new wire from the fusebox to the coil and messed with the wires / plug onthe dizzy (the hall sender plug ???)
they told me the ignition leads were arcing and they needed replacing so rather than let them mess around with it anymore i drove it back to work and ordered some leads.
after fitting the new leads she started first time then after a minute or so she cut out.
Ive tested for 12v to the coil which is there then removed a plug but ive got no spark (theres fuel so presume pump and relay are working fine) then removed king lead also no spark.
Im thinking its the hall sender or wires/connector that is the problem
The garage seemed to think the ignition amplifier could be the problem with the cutting out so im thinking mabey a combination of the two is the problem.
A mate at work says he can tell me what the problem is if i can get the schematics ( hes an electrical wizzard)
can I replace the hall sender or do i need to replace the dizzy? presume if i remove the circlip on the shaft i can get at the wires??
any ideas??

ps sorry about the novel

cheers davow