My 76 cadillac ambulance will crank and run till it gets warm then shuts off like you turned the key off. I will let it sit 5-10 minutes and will crank back but only run a couple minutes then shut off again. It seems like an electrical issue but I have put a new coil, rotator, ignition module, and new connections but still have the same issue. I wanted to see if you guys have any other suggestions or experiences with something like this.