Grand Marquis V8-281 4.6L SOHC (1992)
Backup Lamp: Description and Operation
The Backup/Neutral Safety Switch has two separate sets of contacts and neutral safety switch contacts. The neutral safety switch contacts are part of the
Starting System and the Electronic Engine Control System.
With the Ignition Switch in RUN voltage is present at the backup lamp switch part of the Backup/Neutral Safety Switch through Fuse 17. When the
transmission is shifted into REVERSE, current flows through Fuse 17, the backup lamp switch contacts and circuit 140 (BK/PK) to the Backup Lamps.
The Backup Lamps illuminate.
The backup lamp switch contacts are also part of the Keyless Entry System. When the transmission is shifted into or through REVERSE, the backup
lamp switch contacts close, applying voltage to pin 10 of the Keyless Entry Module. This prompts the Module to automatically lock all doors (if other
conditions are met).
