GMC Forward Control P3500 (1985-1999) (eng harn Wiring diagrams

3 4 5 PNK PNK WIRE A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FUEL GAUGE FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP MAP REF LO MASS AIR FLOW SENSOR (MAF) (MOUNTED IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) NCA WIRE ORG/ WIRE PNK 6 7 8 9 10 11 12 13 14 15 WIRE PNK PNK PNK 2 3 4 5 WIRE PNK PNK WIRE PNK WIRE PPL RED WIRE RED/BLK WIRE REF LO REF THROTTLE POSITION (TP) SENSOR (ON THROTTLE BODY, TOP OF ENGINE) SENSOR BREAKOUT) SPEEDO- METER TACHO- METER TAN WIRE TEMP WHT WIRE YEL WIRE

3 4 5 6 7 8 9 10 11 12 13 14 15 16 PNK PNK WIRE A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FROM TPS BREAKOUT) FUEL GAUGE FUEL PUMP SWITCH, ENGINE OIL PRESSURE GAUGE SENSOR (TOP LEFT REAR OF ENGINE) FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP REAR OF ENGINE) MAP REF LO MASS AIR FLOW SENSOR (MAF) (MOUNTED IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK PNK PNK 2 3 4 5 WIRE PNK PNK WIRE PNK WIRE PPL RED WIRE RED/BLK WIRE REF LO TEMP REF THROTTLE POSITION (TP) SENSOR (ON THROTTLE BODY, TOP OF ENGINE) SENSOR BREAKOUT) SPEEDO- METER TACHO- METER TAN WIRE WHT WIRE YEL WIRE

5 6 7 8 9 10 11 12 PNK PNK WIRE A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FROM TP SENSOR BREAKOUT) FUEL GAUGE FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN, START I/P FUSE BLOCK (BEHIND DASH PANEL) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MAP MASS AIR FLOW (MAF) SENSOR (MOUNTED IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) NCA WIRE ORG/ WIRE PNK 10 11 12 13 14 15 16 17 WIRE PNK 5 6 WIRE PNK PNK PNK PNK 1 2 3 4 WIRE PNK WIRE PPL PPL 1 2 PPL 8 9 RED WIRE RED/BLK WIRE REF LO REF LO TEMP REF THROTTLE POSITION (TP) SENSOR (ON THROTTLE BODY, TOP OF ENGINE) SERVICE ENGINE SOON INDICATOR SPEEDO- METER TACHO- METER TAN WIRE TRANS FUSE 17 WHT WIRE YEL WIRE

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (REAR OF A/C COMPRESSOR) BLK WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG-B FUSE 10 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) FROM ECT SENSOR BREAKOUT) FROM MAF SENSOR BREAKOUT) FROM TP SENSOR BREAKOUT) FUEL GAUGE FUEL PUMP SWITCH, ENGINE OIL PRESSURE GAUGE SENSOR (TOP LEFT REAR OF ENGINE) FUEL SENDER, FUEL PUMP (TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) INSTRUMENT CLUSTER INTAKE AIR TEMPERATURE (IAT) SENSOR (IN FRESH AIR INTAKE, BEHIND AIR FILTER BOX) LT BLU/WHT WIRE LT GRN WIRE MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP RIGHT REAR OF ENGINE) MAP MASS AIR FLOW (MAF) SENSOR (IN FRESH AIR INTAKE BEHIND AIR FILTER BOX) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK 10 11 12 13 14 15 16 17 WIRE PNK 5 6 WIRE PNK PNK PNK PNK 1 2 3 4 WIRE PNK PNK WIRE PNK WIRE PPL PPL 1 2 PPL 8 9 RED WIRE RED/BLK WIRE REF LO REF LO TEMP REF THROTTLE POSITION (TP) SENSOR (THROTTLE BODY, TOP OF ENGINE) SERVICE ENGINE SOON INDICATOR SPEEDO- METER TACHO- METER TAN WIRE TRANS FUSE 17 WHT WIRE YEL WIRE

BATTERY JUNCTION BLOCK (LEFT SIDE OF ENGINE BULKHEAD, ABOVE RELAY BRACKET) BLK WIRE BULKHEAD GROMMET) CRK (START) DK BLU WIRE FROM GENERATOR B+ BREAKOUT) FUEL INJECTION PUMP COLD ADVANCE SOLENOID (IN FUEL INJECTION PUMP) FUSIBLE LINK (16 GA- GAUGES FUSE GLOW PLUGS HOT AT ALL TIMES HOT IN (ON) RUN, START (CRANK) I/P FUSE BLOCK (DASH PANEL PROVIDED BY BODY BUILDER) (BODY BUILDER INSTALLED) IGNITION SWITCH INSTRUMENT CLUSTER LOCK ON (RUN) OFF LT GRN/BLK WIRE NCA WIRE PNK IGN FEED IND LAMP OUT GROUND WIRE PNK WIRE POWER DISTRIBUTION SYSTEM PPL PPL STUD RED WIRE STARTER RELAY (ENGINE BULKHEAD RELAY BRACKET UNDER BATTERY JUNCTION BLOCK) STARTER SOLENOID (STARTER AT LOWER RIGHT SIDE OF ENGINE) STUD WATER IN FUEL WHT WIRE YEL WIRE YEL/BLK WIRE

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT FOR CRUISE CONTROL MODULE, TOWARD RELAYS) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE SENSOR (ON TOP FRONT OF ENGINE) FUEL GAUGE FUEL PUMP MODULE (ON TOP OF FUEL TANK) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK IN PCM BREAKOUT, 20 CM FROM MAIN HARNESS TOWARD FUEL PUMP RELAY) INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP (MIL) "SERVICE ENGINE SOON" MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP CENTER FRONT OF ENGINE) MASS AIR FLOW SENSOR (RIGHT FRONT OF ENGINE COMP, ON AIR INTAKE ASSEMBLY) NCA WIRE ORG/ WIRE PNK 16 17 18 19 20 21 WIRE PNK 22 23 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE RED WIRE RED/BLK WIRE SPEED METER TACH THROTTLE POSITION SENSOR (ON THROTTLE BODY, TOP OF ENGINE) TRANS FUSE 17 WHT WIRE YEL WIRE

A/C COMPRESSOR HIGH PRESSURE CUT-OFF SWITCH (ON REAR OF A/C COMPRESSOR) BLK WIRE BREAKOUT FOR CRUISE CONTROL MODULE, TOWARD RELAYS) BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ENG BAT FUSE 10 ENGINE COOLANT TEMPERATURE SENSOR (ON TOP FRONT OF ENGINE) FUEL GAUGE FUEL PUMP AND FUEL TANK SENDER (ON TOP OF FUEL TANK) FUEL PUMP/ OIL PRESSURE SWITCH (ON TOP LEFT REAR OF ENGINE) GAUGES FUSE 8 GRY WIRE HOT AT ALL TIMES HOT IN RUN AND START I/P FUSE BLOCK INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE MALFUNCTION INDICATOR LAMP (MIL) "SERVICE ENGINE SOON" MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR (TOP CENTER FRONT OF ENGINE) MASS AIR FLOW SENSOR (RIGHT FRONT OF ENGINE COMP, ON AIR INTAKE ASSEMBLY) NCA WIRE OIL PRESS GAUGE ORG/ WIRE PNK 22 23 WIRE PNK PNK 2 3 WIRE PNK PNK WIRE PNK WIRE PPL PPL PNK 9 10 11 12 13 14 15 WIRE RED WIRE RED/BLK WIRE SPEED METER TACH TAN WIRE THROTTLE POSITION SENSOR (ON THROTTLE BODY, TOP OF ENGINE) TRANS FUSE 17 WHT WIRE YEL WIRE