Check relay 109 - it gives power to the electronics. You just have to remove the trim under the dashboard to see it. They updated it but never issued a recall. If it's black, replace it with the new gray relay 109. The fact that letting the car cool down is the classic symptom of an early relay 109 overheating. I'll bet that the glow plug light doesn't light when it's stalled out right? That is a dead sure sign.