Diesel Data: Automotive Repair

Backup Lights Circuit

When the ignition switch is either in the ON or the START position, voltage applies through the TURN fuse to one of the following components:
- The backup lamp switch for manual transmission.
- The transmission range switch for automatic transmission.

When the shifter is in the R position, the switch closes. The voltage applies to the backup lamps in the tail lamps. Since the tail lamps are ground permanently at G400, the lamps will light.