I have posting and receiving some good answers. Here is my new story for the Cobalt 05, 2.2L Sedan Automatic.
- New Alternator (Bosch)
- New Battery (1000 AMPS)
It does not have normal voltage readings. It was on 12.0 and 12.26. I took it the Electro-mechanic. He found that the positive screw on the trunk was rusted. They cleaned it and it started reading 13.1 and went to 13.95 and higher (with A/C, lights, radio on).
Came home, tried to start the car, DID'NT want to. Did it for a second time and it started and again reading 12.26 and in less than 5 minutes went to normal 14.0.
He gave me a technical service bulletin issued July 21, 2008 that these cars and some Hummers, Saab by GM have this incident. Extended periods of engine idling, may result in a discharged battery. This was extracted from the Mitchell Repair Information Company, LLC.
I am so sad this is happening. I don't feel save driving this car. Has anyone before had this issue or having it?