Chevrolet 2002 Corvette Owner's Manual page 108

Headlamps Doors
The headlamp doors are designed to open when you
turn the headlamps on, and close when you turn the
headlamps and parking lamps off. If you turn the
headlamps on, then turn back to the parking lamps
setting, the headlamp doors will stay open.
2-50
You can open the doors manually using the knob next to
the headlamp assembly. Turn the knob counterclockwise
until the doors are open. Turn the knob clockwise to
close the doors manually.
The headlamp doors should be open when driving in
icy or snowy conditions to prevent the doors from
freezing closed and when washing the vehicle to help
clean the headlamps.
NOTICE:
In order to avoid possible contact of the hood to
the headlamp doors, either take care in raising
the hood with the headlamps up, or turn off the
headlamps prior to opening the hood.