4wd circuit, without electronic shift control, with light duty transmissio for GMC Cab & Chassis K2500 (1989-2000)

AUXILIARY BATTERY RELAY BLK WIRE BLK/WHT WIRE BRN WIRE DIESEL FRONT AXLE ACTUATOR FUSE 24 GASOLINE GRY WIRE GRY/BLK WIRE HOT IN PARK OR HEAD HOT IN RUN I/P FUSE BLOCK (LEFT SIDE OF DASH, ILLUM FUSE 14 INDICATOR M/T A/T POWERTRAIN CONTROL MODULE (BEHIND RIGHT SIDE OF DASH) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP TRANSFER CASE SWITCH (TOP LEFT OF TRANSFER CASE) VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT)