Last 6th of Jan. my son parked his car, a 2008 Chevy HHR, and 3 hours later it wouldnt start.
Not only wouldn’t start, the Ignition key wouldn’t turn, and he couldn’t remove it.
Checked ECM fuse, Good: Checked Batt. No voltage on the Batt. No corrosion, no loose connections.
Put jumper on it, started right up.
Took it to Advance Auto, Batt showed a CCA of 660 Amps., Alternator putting out 15Volts.
No problems were found. Hasn’t happened since.
Any ideas?
If you had no voltage while measuring the voltage across the actual battery posts then the battery may have a faulty internal connection. If you measured the voltage at some other points then the connections between the points you took the mesurement and the battery need to be considered in the hunt for the trouble.
Key would not turn is the place to start, anti theft or bad lock is a start.