2009 Impala all power dies when trying to start car and key is locked in ignition. Car does not even attempt to start at all... just a click power is gone. No, light, no power lock, no dash or interior lights, no gauges... nothing. A few minutes later I hear a click and then power is restored and key is unlocked and all lights, dash, horn and everything works again. Everything worked fine until I replaced battery 2 days ago. At one point while all power was dead inside I heard a buzzing under the hood. Turned out to be fuel pump release. Had to remove negative battery cable to stop it... negative battery cable was VERY hot. Just looking for any pointers as to what I should be looking for. I've had both alternator and battery tested and they are good. Several months ago I had to repair the shift lock cable as one of the wires had broken. Other than that I've not had to work on anything on the car.