If the drivers door is opened with the ignition off and the lamps on, a warning chime will sound. This indicates that the headlamps are still on.
Chevrolet Cobalt Service & Repair Manual. Ignition Switch, Replace
1.
Remove steering column trim covers.
2.
Disconnect ignition switch harness
connector.
3.
Turn ignition switch to Run position.
4.
Remove ignition switch screws, then
ignit ...