did you go thru the stack of hot wires on the "jumping post" behind the battery? I'd look at all those. Take the battery out and maybe the tray and test each of those wires for continuity also. Those are all the leads for ECM and cabin electrical that do not go thru the fuse block. Each has a fusable link a few inches from the post that they mount on. If thats all in order, then I'd look at the grounds for the harness. The most important one (of about 30) is by the oil filter and has 4 or 5 wires on a bolt. Those are all the grounds for the same circuits that have the fusable links. The only other place to look would be the bulkhead plug by the battery but those are so well sealed that they rarely go bad.
I do get nothing when I turn the key, the dash is blank also, so the security light doesn't flash and there is no chime.But the DIC, the radio and courtesy lights all work, (It's like half the car is dead) I cleaned all battery terminals and connections and measured 12v from battery+ terminal to main starter terminal. I did try the key when i jumped the starter but still nothing. Do you know where I should look next?
My industry was in heavy equipment in construction related services. We specialized in big equipment that pumped concrete in hi-rise bldgs, bridges, under water..etc. All hyd powered with various hyd drive systems and anything from toggle switches for controls to proximity sensors and computers.
I started out as an operator, was sent back to school and grew and moved up thru the ranks over the years. My claim to fame was some published articles on proceedure and diagnostics in emergency situations in the field, where being creative was equally as important as training.
I once made a machine run (elect failure) with a 5 ft section of speaker wire, a wad of chewing gum, a broken tail lite bulb and some luck. No tools available, and a high dollar catastrophy in progress I had to make something happen right now, not in 20 minutes..so I got power from the bulbs element in the socket, held the wire in place with the gum, (really) and ran that wire to the fuse block bar side in the computer control panel. A factory tech drove up, looked at that, looked at me, says "what the hell do ya need me for ?" and walked away....
I enjoyed the challenge more than the money.....Its too bad I had to get old. It used to be fun.
You mentioned that you were an Hydraulics engineer and that made me wonder if you ever did any work in the sugar cane machinery manufacturing. The reason I ask is my cousin was a hydraulics engineer in that field that held several patents and designs for his work in hydraulics on not only sugar cane machinery but oil rigs and aircraft. I know that at one time he did consulting work for a company in Texas and wouldn't it be a small world if the two of you had meant. His name was Leonard A. Karber