GMC Pickup C3500 (1985-2000) fuel pump and sender Wiring diagrams

4.3L A/C COMPRESSOR CLUTCH A/C COMPRESSOR CYCLING SWITCH A/C HIGH PRESSURE (NOT CUTOUT USED) SWITCH AIR REACTION INJECTION (SECONDARY) WATER PUMP VALVE (7.4L ONLY) BALANCE FUEL FUEL PUMP GAGE BALANCE SENDER MODULE BLK WIRE BLK/WHT WIRE BLOWER MOTOR BRAKE PRESSURE WARNING SWITCH CRUISE INSTRUMENT CONTROL CLUSTER MODULE DATA LINK CONNECTOR DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE EVAPORATIVE EMISSIONS PURGE VACUUM SOLENOID SWITCH EXCEPT 4.3L FRONT AXLE ACTUATOR FRONT MODE DOOR MOTOR FRONT TEMPERATURE DOOR MOTOR FUEL PUMP AND SENDER GASOLINE HEATED OXYGEN SENSOR BANK 1 SENSOR 1 HEATED OXYGEN SENSOR BANK 1 SENSOR 2 HEATED OXYGEN SENSOR BANK 2 SENSOR 1 HEATED OXYGEN SENSOR BANK 2 SENSOR 2 HIGH A/C PRESSURE CUTOUT SWITCH HIGH BLOWER MOTOR RELAY IGNITION COIL MODULE MASS AIRFLOW SENSOR PARK/ NEUTRAL POSITION SWITCH POWER STEERING CONTROL MODULE RECIRCULATION DOOR MOTOR STARTER RELAY STOPLAMP RELAY TRANSFER CASE RELAY TRANSFER CASE RELAY BREAKOUT) UNDER- HOOD LAMP UNDERHOOD FUSE- RELAY CENTER A/C COMPRESSOR CLUTCH RELAY UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE VEHICLE UNDER- SPEED HOOD SENSOR REEL (BLUNT CUT) LAMP W/ DUAL TANKS W/O DUAL TANKS (EXCEPT 4.3L) UNDERHOOD FUSE- RELAY CENTER FUEL PUMP RELAY

4.3L ONLY BALANCE FUEL GAGE SENDER BENCH OTHERS SEAT BLK WIRE BLK/WHT WIRE CENTER HIGH MOUNT STOP LAMP CONVENIENCE CENTER CONVENIENCE CENTER (UNDER LEFT SIDE OF I/P) DATA LINK CONNECTOR DIESEL DOOR LOCK RELAY ELECTROCHROMIC REARVIEW MIRROR W/ COMPASS FOUR-WHEEL DRIVE INDICATOR LAMP FUEL GAGE SENDER FUEL PUMP AND SENDER FUEL PUMP BALANCE MODULE INSTRUMENT CLUSTER INTERIOR LAMP CONTROL MODULE LEFT CLEARANCE LAMP LEFT FRONT POWER WINDOW LOCK SWITCH LEFT ILLUMINATED VANITY MIRROR LEFT POWER LUMBAR SUPPORT MOTOR LEFT REAR REAR POWER WINDOW WINDOW LOCKOUT SWITCH SWITCH MASS AIRFLOW SENSOR POWER AMPLIFIER POWER AMPLIFIER RELAY POWER FUEL STEERING PUMP CONTROL RELAY MODULE POWER OUTSIDE REARVIEW MIRROR SWITCH POWERTRAIN CONTROL MODULE REMOTE CONTROL DOOR LOCK RECEIVER RIGHT CLEARANCE LAMP RIGHT FRONT POWER WINDOW SWITCH RIGHT ILLUMINATED VANITY MIRROR RIGHT POWER LUMBAR SUPPORT MOTOR RIGHT POWER POWER LEFT POWER LUMBAR MOTOR SEAT RIGHT REAR POWER WINDOW SWITCH ROOF MARKER LAMPS SEAT BELT SWITCH TAN/WHT WIRE TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP UNDER HOOD FUSE-RELAY CENTER VEHICLE SPEED SENSOR BUFFER WHT/ BLK WIRE

3-2 SHIFT SOLENOID 4.3L ALL OR W/ NRQ ALL OTHER BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU OR TAN/BLK WIRE DK BLU WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER FUEL PUMP IN-LINE FUSE FUEL PUMP OIL PRESSURE SWITCH (LEFT REAR OF ENGINE, NEAR EXHAUST MANIFOLD) FUEL PUMP RELAY (RIGHT REAR OF ENGINE COMPARTMENT, NEAR BATTERY JUNCTION BLOCK) FUSE FUSE LINK (20 GA- GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST Y-PIPE) HOT AT ALL TIMES HOT IN RUN FUSE BLOCK HOT IN RUN OR START INSTRUMENT CLUSTER LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE OIL PRESS IN ONLY ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE PNK/WHT WIRE PPL PPL 4 5 PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SHIFT SOLE- NOID 1-2 SHIFT SOLENOID 2-3 SOLENOID TACH IN TAN WIRE TAN/BLK DK BLU OR WIRE TAN/BLK WIRE TORQUE CONVERTER CLUTCH TRANS FUSE TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

4.3L 4.3L ONLY 7.4L BLK WIRE BLK/WHT WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FUEL PUMP AND SENDER FUEL PUMP IN-LINE FUSE FUEL PUMP OIL PRESSURE SWITCH (LEFT REAR OF ENGINE, NEAR EXHAUST MANIFOLD) FUEL PUMP RELAY (RIGHT REAR OF ENGINE COMPARTMENT, NEAR BATTERY JUNCTION BLOCK) FUSE FUSE BLOCK FUSE LINK (20 GA- GRY WIRE HEATED OXYGEN SENSOR (4.3L) (IN EXHAUST Y-PIPE) HOT AT ALL TIMES HOT IN RUN INSTRUMENT CLUSTER LT BLU/BLK WIRE LT GRN/BLK WIRE OIL PRESS IN ORG/ WIRE ORG/BLK WIRE OXYGEN SENSOR (7.4L) (LEFT EXHAUST MANIFOLD) PNK/BLK WIRE PNK/WHT WIRE PPL PPL/WHT WIRE RED WIRE TACH IN TAN WIRE THROTTLE ACTUATOR SOLENOID (7.4L ONLY) (ON THROTTLE BODY UNIT) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE

3-2 SHIFT SOLENOID 4.3L ALL OR W/ NRQ ALL OTHER BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU OR TAN/BLK WIRE DK BLU WIRE DK GRN/WHT WIRE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER FUEL PUMP IN-LINE FUSE FUEL PUMP OIL PRESSURE SWITCH (LEFT REAR OF ENGINE, NEAR EXHAUST MANIFOLD) FUEL PUMP RELAY (RIGHT REAR OF ENGINE COMPARTMENT, NEAR BATTERY JUNCTION BLOCK) FUSE FUSE LINK (20 GA- GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST Y-PIPE) HOT AT ALL TIMES HOT IN RUN FUSE BLOCK HOT IN RUN OR START INSTRUMENT CLUSTER LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE OIL PRESS IN ONLY ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE PNK/WHT WIRE PPL PPL 4 5 PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SHIFT SOLE- NOID 1-2 SHIFT SOLENOID 2-3 SOLENOID TACH IN TAN WIRE TAN/BLK DK BLU OR WIRE TAN/BLK WIRE TORQUE CONVERTER CLUTCH TRANS FUSE TRANS- MISSION TEMP SENSOR VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

4 5 PPL 423 3 121 PNK WIRE ACCY BLK WIRE BLK/RED WIRE BLK/WHT WIRE BRN WIRE BULB TEST DISTRIBUTOR (CENTER REAR OF ENGINE) DK BLU WIRE DK GRN/WHT WIRE EGR ELEC- TRONIC VACUUM REGULATOR SOLENOID (5.7L H/D ONLY) (RIGHT TOP OF ENGINE) ENGINE COOLANT TEMPERATURE SENSOR (RIGHT TOP FRONT OF ENGINE) FUEL PUMP AND SENDER FUEL PUMP IN-LINE FUSE FUEL PUMP OIL PRESSURE SWITCH (LEFT REAR OF ENGINE, NEAR EXHAUST MANIFOLD) FUEL PUMP RELAY (RIGHT REAR OF ENGINE COMPARTMENT, NEAR BATTERY JUNCTION BLOCK) GRY WIRE HOT AT ALL TIMES IGNITION COIL (CENTER REAR OF ENGINE) IGNITION SWITCH INSTRUMENT CLUSTER KNOCK SENSOR (RIGHT SIDE OF ENGINE, BELOW EXHAUST MANIFOLD) KNOCK SENSOR MODULE (ABOVE RIGHT SIDE ROCKER COVER) LOCK OFF LT BLU/BLK WIRE LT GRN WIRE LT GRN/BLK WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (RIGHT REAR TOP OF ENGINE) NCA WIRE OIL PRESS IN ORG/ WIRE PNK WIRE PNK/BLK WIRE PPL PPL/WHT WIRE RED WIRE RUN WIRE TACH IN TACHOMETER TEST LEAD TAN WIRE TAN/BLK WIRE THROTTLE POSITION SENSOR (RIGHT SIDE OF THROTTLE BODY) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT SIDE END OF I/P) VSS IN WHT WIRE YEL WIRE YEL/BLK WIRE

3-2 SHIFT SOLENOID ALL EXCEPT 5.7L W/ BLK WIRE BLK/WHT WIRE BRN OR TAN/BLK WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B MINI FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION FUEL PUMP AND SENDER FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE NEAR DISTRIBUTOR) FUEL PUMP PRIME CONN- ECTOR FUEL PUMP RELAY (UNDERHOOD FUSE/RELAY CENTER) GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST Y-PIPE) HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND LEFT SIDE OF I/P) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE OIL PRESS IN ONLY ORG/ WIRE PNK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SHIFT SOLE- NOID 1-2 SHIFT SOLENOID 2-3 SOLENOID TACH IN TAN WIRE TAN/BLK BRN OR WIRE TAN/BLK WIRE TORQUE CONVERTER CLUTCH TRANS FUSE 20 TRANS- MISSION TEMP SENSOR UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

423 3 121 PNK WIRE ACCY BLK WIRE BLK/WHT WIRE BRN WIRE BULB TEST DISTRIBUTOR (CENTER REAR OF ENGINE) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE EGR ELEC- TRONIC VACUUM REGULATOR SOLENOID (5.7L H/D ONLY) (RIGHT TOP OF ENGINE) ENGINE COOLANT TEMPERATURE SENSOR (FRONT OF LEFT CYLINDER HEAD) FUEL PUMP AND SENDER FUEL PUMP CYCLE MODULE (5.7L H/D ONLY) FUEL PUMP PRIME CONNECTOR FUEL PUMP RELAY (UNDERHOOD FUSE/RELAY CENTER) GRY WIRE HOT AT ALL TIMES IGNITION COIL (CENTER REAR OF ENGINE) IGNITION SWITCH INSTRUMENT CLUSTER KNOCK SENSOR (RIGHT SIDE OF ENGINE, BELOW EXHAUST MANIFOLD) KNOCK SENSOR MODULE (ABOVE RIGHT SIDE ROCKER COVER) LOCK OFF LT GRN WIRE LT GRN/BLK WIRE MANIFOLD ABSOLUTE PRESSURE SENSOR (RIGHT REAR TOP OF ENGINE) NCA WIRE OIL PRESS IN ORG/ WIRE PNK 21 22 WIRE PNK WIRE PPL/WHT WIRE RED WIRE RED/BLK WIRE RUN WIRE TACH IN TACHOMETER TEST LEAD TAN WIRE TAN/BLK WIRE THROTTLE POSITION SENSOR (RIGHT SIDE OF THROTTLE BODY) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE YEL WIRE YEL/BLK WIRE

BLK WIRE BLK/WHT WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B MINI FUSE FUEL PUMP AND SENDER FUEL PUMP OIL PRESSURE SWITCH/SENDER (LEFT LOWER FRONT OF ENGINE, NEAR DAMPER) FUEL PUMP PRIME CONN- ECTOR FUEL PUMP RELAY (UNDERHOOD FUSE/RELAY CENTER) GRY WIRE HEAVY DUTY ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION HOT AT ALL TIMES HOT IN RUN OR START I/P FUSE BLOCK (BEHIND LEFT SIDE OF I/P) IDLE SPEED CONTROL ACTUATOR (ON THROTTLE BODY UNIT) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE NCA WIRE OIL PRESS IN ORG/ WIRE OXYGEN SENSOR (EXHAUST PIPE NEAR CROSSOVER) PNK WIRE PPL PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SHIFT SOLENOID 1-2 SHIFT SOLENOID 2-3 TORQUE CONVERTER CLUTCH SOLENOID TACH IN TAN WIRE TRANS FUSE 20 TRANS- MISSION TEMP SENSOR UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE YEL/BLK WIRE

4.3L ONLY BLK WIRE BLK/WHT WIRE BRN WIRE DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM-B MINI FUSE FUEL PUMP AND SENDER FUEL PUMP OIL PRESSURE SWITCH (TOP REAR OF ENGINE NEAR DISTRIBUTOR) FUEL PUMP PRIME CONN- ECTOR FUEL PUMP RELAY (UNDERHOOD FUSE/RELAY CENTER) GRY WIRE HEATED OXYGEN SENSOR (IN EXHAUST Y-PIPE) HOT AT ALL TIMES IDLE SPEED CONTROL ACTUATOR SOLENOID (7.4L ONLY) (SIDE OF THROTTLE BODY UNIT) INSTRUMENT CLUSTER LT GRN/BLK WIRE OIL PRESS IN ORG/ WIRE PNK WIRE PPL PPL/WHT WIRE RED WIRE TACH IN TAN WIRE UNDERHOOD FUSE/RELAY CENTER (LEFT REAR OF ENGINE COMPT) VEHICLE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) VSS IN WHT WIRE WHT/BLK WIRE