During backup lamp operation, power is supplied from the B/U LP fuse in the underhood fuse block when the ignition switch is in the RUN or the START position. Current flows through CKT 839 (PNK) to the park/neutral position switch (with automatic transmission) or to the backup lamp switch (with manual transmission). When the transmission is placed in REVERSE, the switch closes. This provides power to CKT 1524 (GRY). CKT 1524 supplies power to the VEH B/U fuse in the underhood fuse block. Current flows from the fuse through CKT 1324 (LT GRN) to SP400 where the current splits to the RH and LH backup lamps. The RH backup lamp receives ground through CKT 2250 (BLK) to G422. The LH backup lamp receives ground through CKT 1750 (BLK) to G475.