The air bag lamp simply means that the air bag computer has detected a
problem with or affecting the restraint system.  To find out the nature of
the problem, you'll need to take the car to a shop with diagnostic
equipment capable of reading the diagnostic trouble codes from the air bag
computer.

The petcock in the bottom of the radiator comes out like an oil pan drain
plug.  Be sure to not lose the rubber gasket when you remove the
draincock.