While driving down the road, the engine will suddenly stop. Just prior to the engine stopping, the speedometer and tachometer will go to zero, and the odometer says "BUS" which a mechanic has told me is the bus bar. But the same mechanic does not know the actual problem. And after a period of time, anytime from one minute to 30 mins after it stops, the engine will start again. Does anyone have any ideas of how I can fix this?