A couple of years ago, our Corvette decided not to start. It was working fine and then when out on a run, it decided not to start. Push the start button and there were some hums and clicks but not starter engagement. We costed down a grade and jump started it on the clutch. Turned out to be the battery, so we put in a new Delco unit. Now, it is doing the same thing again but won't even start when jumpered to a good battery. The mechanic that I use and trust is on holidays for another week. Anyone else had this problem?