Doug, I don’t think that you are missing anything. The level of published electrical info on our cars is really quite poor, considering. I’m not aware of any relevant dash wiring details, only as you say the chassis and engine harness’s from the parts book. They aren’t particularly reliable either when you start delving into them. I’ve seen no information either on the PCB other than the various photo’s floating around, that’s all there was to go on.
I originally dropped the dash to do an initial recky. I took loads of photos and measurements. I then went away and built the replacement bits in slow time over the winter. I tested it at leisure on the bench. When it was ready it took less than a day to fit.
Regarding the instrument warning lights, it’s fairly obvious just by looking that they are in fact LED’s and the current limiting resistor array can me identified on the PCB photos.
The mystery third red wire in the pic is a spare 12v supply that I just cut off and left inside the loom. I had one too many wires connected, sorry for the confusion. The second pin.1 is now pin.9….
