It is a super easy repair and I was quite amazed that is was something so basic as poor soldering. It was a production problem that lasted throughout the D1 model manufacturing and I'd guess there isn't one in a junkyard that doesn't need the same attention to detail.

My 2 bits -- try the window without the card slid into the slot.. just connected and hanging in a SAFE - non metallic way. I had one case of a card that would work until it was slid all the way in. I assume there was another weak spot that I could not find and when slid in, it was putting pressure on the right spot to prevent it from working. I ended up leaving it about an inch out of the holder.

right around the 6 min mark he shows the bad solder joint.

Thanks for the guidance! I ended up jumping around the ECU like its described in the Atlantic British instructions, however, I used my own wires and connectors. Thought paying $20 for that was a little unnecessary and I didn't want to wait on shipping. The job was very simple once figured out the problem.

Once I finished wiring it and gave it a try.... you all prolly already know what happened... rolled it down once and the little plastic circle son off a B broke... LOL!

I found this video a while ago and was impressed how well he was working on this project - I know how hard that card is to get out without lowering that enclosure. Skill and persistence.