Caprice RWD V8-305 5.0L (1992)
Backup Lamp: Description and Operation
Voltage is applied to the Transmission Position Switch with the Ignition Switch in "RUN", "BULB TEST" or "START". When the Transmission is
shifted into "Reverse", the Transmission Position Switch closes the circuit and voltage is applied to the Backup Lamps. The Lamps are permanently
grounded.