Backup Lamp: Description and Operation

The B/U fuse in the engine wiring harness junction block supplies battery positive voltage to the normally open backup lamp switch. When driver places the gear selector lever is in the REVERSE position, the backup lamp switch closes and the current flow is from the backup lamp switch through the VEH B/U fuse to the backup lamps. The backup lamps are grounded at G475 and G422 on the pickup and G450 on the utility.