My indicator light is telling me I have a burned out bulb somewhere in or on the car (1992 SC400) I have looked at every bulb I can find and all are working. Is there some obscure bulb somewhere that I might have missed? I have checked all the marker lights, headlights, tail lights, license plate lights, interior lights etc.

 

Check the bulbs and sockets for corrosion if you haven't already. The bulbs can get pretty nasty over the years. When I changed all the factory installed bulbs on the 90 LS400 I used to have after about 10 years, the glass globes on the bulbs were blackened although they still put out light. I once had a bulb out warning on the same car that I finally traced to a loose connection on a trailer light harness that was connected to the car's left taillight wires - weird because all the car lights and my trailer lights worked fine.

Also verify that the bulbs are the correct type. A single filament bulb in a socket requiring a double filament bulb can cause the warning light.