Chevrolet Cab & Chassis C3500 (1989-2000) red Wiring diagrams

1-2 SHIFT SOL TCC SOL 2-3 SHIFT SOL 3-2 SHIFT SOL 999 998 961 452 1586 995 PPL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCE- LERATOR BRACKET) APP #3 APP #3 SENSOR SIG APP 1 BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE DATA LINK CONNECTOR (BELOW LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE ECM IGN FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) FUSIBLE LINK GRY WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START HOT IN START OR RUN FUSE BLOCK TRANS FUSE IGNITION FEED 3-2 CONTROL SOL DIAGNOSTIC REQUEST LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE PPL PPL APP #2 PPL TCC/BRAKE SW PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) TAN WIRE TAN/BLK WIRE TCC/ BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) TRANS FLUID TEMP (TFT) SENSOR TRANSFER CASE SWITCH VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCE- LERATOR BRACKET) APP #3 APP #3 SENSOR SIG APP 1 BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE DATA LINK CONNECTOR (BELOW LEFT SIDE OF I/P) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ECM IGN FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) FUSIBLE LINK GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START HOT IN START OR RUN FUSE BLOCK TRANS FUSE IGNITION FEED TCC DIAGNOSTIC REQUEST LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE PPL PPL APP #2 PPL TCC/BRAKE SW PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) TAN WIRE TCC SOL 2-3 SHIFT SOL TCC/ BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) TRANS FLUID TEMP (TFT) SENSOR TRANS INPUT SPD SIG LO TRANSFER CASE SWITCH TRANSMISSION INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL ACCELERATOR PEDAL POSITION (APP) MODULE (TOP OF ACCE- LERATOR BRACKET) APP #3 APP #3 SENSOR SIG APP 1 BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRN WIRE BRN/WHT WIRE DATA LINK CONNECTOR (BELOW LEFT SIDE OF I/P) DK BLU WIRE DK BLU/WHT WIRE DK GRN WIRE ECM IGN FUSE ELECTRONIC 4-SPEED AUTOMATIC OVERDRIVE TRANSMISSION ENGINE COOLANT TEMPERATURE (ECT) SENSOR (RIGHT SIDE OF ENGINE) FUSIBLE LINK GRY WIRE GRY/RED WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START HOT IN START OR RUN FUSE BLOCK TRANS FUSE IGNITION FEED TCC DIAGNOSTIC REQUEST LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE ORG/BLK WIRE PNK WIRE PNK/BLK WIRE POWERTRAIN CONTROL MODULE PPL PPL APP #2 PPL TCC/BRAKE SW PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) TAN WIRE TCC SOL 2-3 SHIFT SOL TCC/ BRAKE SWITCH (ON BRAKE PEDAL SUPPORT BRACKET) TRANS FLUID TEMP (TFT) SENSOR TRANS INPUT SPD SIG LO TRANSFER CASE SWITCH TRANSMISSION INPUT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF I/P) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1-2 SHIFT SOL 2-3 SHIFT SOL 3-2 SHIFT SOL TRANS FLUID TEMP (TFT) SENSOR BLK WIRE BLK/WHT WIRE BLK/YEL WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE DATA LINK CONNECTOR (BELOW LEFT SIDE OF DASH) DK BLU WIRE DK BLU/WHT WIRE ECM I FUSE ECM-B FUSE ENGINE COOLANT TEMPERATURE (ECT) SENSOR (TOP FRONT OF ENGINE) GAGES FUSE 4 GRY WIRE HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK INSTRUMENT CLUSTER LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE ORG/ WIRE PNK WIRE POWERTRAIN CONTROL MODULE (PCM) (UNDER RIGHT END OF DASH) PPL PPL PNK WIRE PPL/WHT WIRE PRESSURE CONTROL SOLENOID RANGE MODE SELECTOR RED WIRE RED/BLK WIRE SERVICE ENGINE SOON SPEED SENSOR (LEFT REAR SIDE OF TRANSMISSION) TAN WIRE TCC/STOPLAMP SWITCH (ON BRAKE PEDAL BRACKET) THROTTLE POSITION SENSOR (RIGHT SIDE OF TBI) TRANS FUSE 20 TRANSMISSION TRANSMISSION INPUT SHAFT SPEED SENSOR (FRONT OF TRANSMISSION) UNDERHOOD FUSE/RELAY CENTER VEHICLE SPEED SENSOR BUFFER (UNDER RIGHT END OF DASH) WHT/BLK WIRE YEL WIRE YEL/BLK WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C DISABLE AUX FAN CTRL IGNITION A/C COMPRESSOR CLUTCH A/C COMPRESSOR CLUTCH CYCLING SWITCH (IN LOW PRESSURE LINE NEAR COMPRESSOR) A/C COMPRESSOR CLUTCH RELAY (IN UNDERHOOD FUSE/RELAY CENTER) A/C CTRL A/C HIGH PRESSURE CUTOUT SWITCH (AT A/C COMPRESSOR) A/C MAXI FUSE 3 CENTER A/C REQ AUX FAN MINI FUSE AUXILIARY COOLING FAN A/C PRESSURE SWITCH AUXILIARY COOLING FAN MOTOR AUXILIARY COOLING FAN RELAY (7.4L VIN J) (IN UNDERHOOD FUSE/RELAY CENTER) BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER MOTOR BLOWER RESISTOR (UNDER RIGHT SIDE OF I/P, ON HEATER HOUSING) BLOWER SWITCH BRN WIRE DIODE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE GAS DIESEL GRY WIRE GRY/BLK WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER I/P ON TOP OF HEATER-A/C CASE) HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START IGN MINI FUSE A/C COMP MINI FUSE HOT IN RUN, BULB TEST OR START FUSE BLOCK HTR A/C FUSE 12 IGN E MINI FUSE LT BLU WIRE LT GRN WIRE NCA WIRE OFF LO ORG/ WIRE PNK WIRE PPL REAR DEFOGGER SYSTEM RECIRCULATION DOOR MOTOR (UNDER I/P ON HEATER- A/C CASE) RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY UNDERHOOD FUSE-RELAY CENTER VALVE CTRL AIR TEMP DR SENSOR MODE SIGNAL A/C SWITCH WATER VALVE (SUBURBAN, UTILITY, CREW CAB ONLY) (RIGHT CENTER OF INTAKE AREA) WHT WIRE YEL WIRE

ANTI-LOCK IND BATT GROUND BLK WIRE BLK/WHT WIRE BRAKE IND BRAKE PRESSURE WARNING LAMP WARNING (ON MASTER BRAKE CYLINDER) BRAKE WARN IND GROUND BRN WIRE CONVENIENCE CENTER DATA LINK CONNECTOR DIODE (BEHIND LEFT SIDE OF I/P) DK GRN WIRE HOT AT ALL TIMES UNDERHOOD FUSE/RELAY CENTER MAXI- FUSE 4 HOT IN RUN BRAKE FUSE 18 HOT IN RUN, BULB TEST OR START FUSE BLOCK GAGES FUSE 4 IGN FEED ABS IND BRAKE SW INSTRUMENT CLUSTER LEFT FNT SENS LO LEFT FRONT WHEEL SENSOR LT BLU WIRE LT GRN/BLK WIRE PNK WIRE PPL PPL/WHT WIRE RED WIRE RIGHT FRONT WHEEL SENSOR RT FNT SENS LO LEFT FNT SENS HI RT FNT SENS HI TAN WIRE TAN/WHT WIRE TCC/STOPLAMP SWITCH (TOP OF BRAKE PEDAL) VEHICLE SPEED SENSOR (LEFT REAR OF TRANS) VSS BUFFER INPUT DLC WHT WIRE YEL WIRE

BLK WIRE BRN WIRE FRT WPR FUSE 11 FUSE BLOCK HOT IN ACCY OR RUN MIST NCA WIRE OFF PULSE PPL RED WIRE SOLID STATE WASH PULSE SWITCH WINDSHIELD WASHER MOTOR WIPER MOTOR MODULE WIPER/ WASHER SWITCH YEL WIRE

1 2 3 4 5 6 7 8 9 10 ILLUMINATION GROUND A/C MAXI FUSE 3 AIR TEMP DR SENSOR MODE SIGNAL BATTERY IGNITION GROUND DEFOGGER ELEMENT BLK WIRE BLOWER MOTOR BLOWER RESISTOR (UNDER RIGHT SIDE OF I/P, ON HEATER HOUSING) BLOWER SWITCH BRN WIRE DK BLU WIRE DK GRN WIRE FRONT MODE DOOR MOTOR (UNDER I/P ON HEATER- A/C CASE) FRONT TEMPERATURE DOOR MOTOR (UNDER I/P ON HEATER- A/C CASE) FUSE BLOCK GRY WIRE HEATER AND A/C CONTROL MODULE HIGH BLOWER RELAY (UNDER I/P ON TOP OF HEATER-A/C CASE) HOT IN RUN HTR A/C FUSE 12 LT BLU WIRE OFF LO ORG/ WIRE PPL REAR DEFOGGER SYSTEM RECIRC CTRL IGNITION RECIRCULATION DOOR MOTOR (UNDER I/P ON HEATER- A/C CASE) RED WIRE TAN WIRE UNDERHOOD FUSE-RELAY CENTER WHT WIRE YEL WIRE

4 WHEEL DRIVE LOW (UNDER RIGHT END OF I/P) SIGNAL AUTOMATIC TRANSMISSION ONLY BLK WIRE BRN WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE FRONT AXLE ACTUATOR SOLENOID (RIGHT SIDE OF FRONT DRIVE AXLE) FRONT AXLE SOLENOID SWITCH (RIGHT REAR SIDE OF FRONT DRIVE AXLE) FUSE GRY WIRE HOT IN RUN I/P FUSE BLOCK INDICATOR LAMP INSTRUMENT CLUSTER LT BLU WIRE PANEL DIMMER SWITCH (ASSEMBLY) PANEL LPS FUSE PICKUP PNK/WHT WIRE POWERTRAIN CONTROL MODULE PPL PPL PPL RED WIRE RWAL DIODE MODULE (UNDER LEFT SIDE OF I/P) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP (AT TRANSFER CASE SELECTOR LEVER) TRANSFER CASE RELAY (RIGHT REAR OF ENG COMPT, NEAR BATTERY JUNCTION BLOCK) TRANSFER CASE SWITCH (LEFT TOP OF TRANSFER CASE) TRANSFER CASE SYNCRONIZER

4 WHEEL DRIVE LOW (UNDER RIGHT END OF I/P) SIGNAL AUTOMATIC TRANSMISSION ONLY BLK WIRE BRN WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF I/P) DK BLU WIRE DK GRN WIRE FRONT AXLE ACTUATOR SOLENOID (RIGHT SIDE OF FRONT DRIVE AXLE) FRONT AXLE SOLENOID SWITCH (RIGHT REAR SIDE OF FRONT DRIVE AXLE) FUSE GRY WIRE HOT IN RUN I/P FUSE BLOCK INDICATOR LAMP INSTRUMENT CLUSTER LT BLU WIRE PANEL DIMMER SWITCH (ASSEMBLY) PANEL LPS FUSE PICKUP PNK/WHT WIRE POWERTRAIN CONTROL MODULE PPL PPL PPL RED WIRE RWAL DIODE MODULE (UNDER LEFT SIDE OF I/P) TRANSFER CASE MODE SELECTOR ILLUMINATION LAMP (AT TRANSFER CASE SELECTOR LEVER) TRANSFER CASE RELAY (RIGHT REAR OF ENG COMPT, NEAR BATTERY JUNCTION BLOCK) TRANSFER CASE SWITCH (LEFT TOP OF TRANSFER CASE) TRANSFER CASE SYNCRONIZER