electrical sucks, you def. have a wire that is bare somewhere though. You may want to use a test light or multimeter to check some of the wires downstream when cutting the wheel to the left and to the right. But if the ecu has no power I'd say it's ignition wire, or the signal wire going to the ecu from the ign. You're losing a main power source when the wheel is cut left. I'd check the fsm's on the old site and see what you can come up with using the diagrams.