93 cabby various electrical issues: diagram and tips humbly requested

I've had a bit of work undertaken recently and everyone denies touching the parts that have failed:
1: no tell-tale dash indications of indicators. I've stripped the dash and all connections seem ok. The green light is very dim when operating and only barely visible when dark. Mot soon and I need this working. 
2: electric windows have been 100% reliable to date. On return they only operated when drivers door was open (I.e. interior light switch earthed). Took back to alarm installer who claimed it wasn't them, but cut the link between door switch and control relays. Then they worked continually: without ignition being on. I've clearly disturbed something as now they don't work at all. 
3: new emerald ecu that seems to hold a map for ten minutes and when plugged in the throttle pot jumps around a bit, causing rough running. Undrivable rough running. Rolling road chap reckons bad earth: as he placed the oscilloscope and noted the ecu earth sitting at c2V (he was connected direct to battery) and a noticeable peak on volts to c4V with a corresponding dip on ignition live. I've re-earthed the ecu and as expected no change. Which makes me think there's an ignition drop out on load of some sort. 

My Haynes manuals are all for other cars and lock the detail I need for the tracing of the ignition live. I did have to replace the ignition switch about ten years ago and have installed headlight wiring loom to alleviate barrel ignition switch loading.  
The annoying thing is, I'm £5k down on the 'upgrade' to rectify a slight stutter and I've been left with an undrivable car that needs further attention. I'll do what I can but if anyone has any obvious steers where I can look or full wiring diagrams I'd appreciate it. Two years the car has been 'nearly' running and another summer missed. Now eating me. I've never glanced so much at the swan vestas 😡😡😡

I found the information here really helpful in finding out I had missing circuits in my new engine loom

https://clubgti.com/forums/index.php?threads/fusebox-faq.219775/#post-1945623

I’d pay good attention to the fuse box earths and maybe remove & check the multi plugs to ensure you don’t have any burnt circuits.. you should be able to trace out the wiring to the dash indicators and electric windows

I assume the indicators do work, if not check the fuse!

Thanks, I'll download and print those for reference. 
Indicators do work as normal but just no tell-tales on instrument cluster. 
I've got the dash components in bits at present so should be as easy as it gets without the full dash out.