Back-up lamps circuit for GMC Cab & Chassis C3500 (1985-2000)

BLK WIRE HOT IN RUN OR START I/P FUSE BLOCK LEFT BACK-UP LAMP LT GRN WIRE MIRRORS SYSTEM (AUTOMATIC DAY/NIGHT MIRROR) PNK A/T WIRE PNK M/T WIRE PNK WIRE RIGHT BACK-UP LAMP TRAILER TOW CONNECTOR TRANSMISSION RANGE SWITCH (LEFT SIDE OF TRANSMISSION) TURN B/U FUSE 16