If the HV battery pack was bad, you'd get codes. You have to get to the "Ready" light. That's where your focus should be. Here's what I would do: Go to your 3rd gen I that "runs and drives fine", cycle the ignition to start and hold for 3 seconds, note everything that happens (specifically when the "Ready" light comes on, what noises you hear and what does the immobilizer light on the radio do. Then have a key cut for that car (don't program it just have it cut so it turns the cylinder). Turn the ignition switch to start and note all that happens (or doesn't happen). Then compare that to your broke Gen I. In order to move forward, we have to eliminate the key as the problem. I'm not convinced the key is not the problem. Are you?