GMC Pickup C3500 (1985-2000) blk Wiring diagrams

ALL OTHERS BATTERY BLK (OR RED) WIRE BLK WIRE BRN WIRE CHARGE WARNING INDICATOR FUSIBLE LINK GAUGES FUSE 4 GENERATOR HOT IN RUN, START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INSTRUMENT CLUSTER MEGA FUSE BLOCK (ON RIGHT FRONT OF ENGINE COMPARTMENT, NEAR BATTERY) PNK 22 WIRE POWER DISTRIBUTION SYSTEM RED WIRE UPLEVEL/ ENHANCED

A/T A/T PPL/ PPL BATTERY BLK WIRE BULB TEST CLUTCH PEDAL POSITION SWITCH (ON TOP OF CLUTCH PEDAL BRACKET) I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) CRANK FUSE 8 IGN A FUSE 6 IGNITION SWITCH LOCK OFF M/T MEGA FUSE BLOCK (ON RIGHT FRONT OF ENGINE COMPARTMENT, NEAR BATTERY) PARK/ NEUTRAL POSITION SWITCH (ON LEFT SIDE, CENTER OF TRANSMISSION) PPL RED WIRE REMOTE BATTERY STUD RUN WIRE STARTER MOTOR STARTER RELAY STARTER SOLENOID WHT WIRE YEL WIRE

ALL OTHERS BATTERY BLK (OR RED) WIRE BLK WIRE BRN WIRE CHARGE WARNING INDICATOR FUSIBLE LINK GAUGES FUSE 4 GENERATOR HOT IN RUN, START I/P FUSE BLOCK (UNDER LEFT SIDE OF DASH) INSTRUMENT CLUSTER MEGA FUSE BLOCK (ON RIGHT FRONT OF ENGINE COMPARTMENT, NEAR BATTERY) PNK 22 WIRE POWER DISTRIBUTION SYSTEM RED WIRE UPLEVEL/ ENHANCED

BLK WIRE BRAIDED GROUND STRAP CARGO DOOR JAMB SWITCH (SUBURBAN/ UTILITY ONLY) COURTESY LAMPS CTRL CTSY FUSE 3 DOME DEFEAT DOOR JAMB DOOR LOCK CONTROL MODULE (IN FRONT OF LEFT REAR WHEELWELL) FRONT DOME/ READING LAMPS GRY WIRE HEADLAMP, PANEL DIMMER SWITCH DOME LAMP DEFEAT HORN FUSE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START I/P FUSE BLOCK GAGES FUSE 4 I/P COMPART- MENT BOX LAMP I/P FUSE BLOCK IGN SW INTERIOR LAMP CONTROL MODULE (UNDER CENTER OF DASH) LAMP OUT LEFT FRONT DOOR COURTESY LAMP (IF EQUIPPED) LEFT FRONT DOOR JAMB SWITCH LEFT I/P COURTESY LAMP LEFT ILLUMINATED VANITY MIRROR LEFT REAR DOOR COURTESY LAMP (IF EQUIPPED) LEFT REAR DOOR JAMB SWITCH (IF EQUIPPED) MIRRORS SYSTEM NCA WIRE ORG/ WIRE OVERHEAD CONSOLE LAMPS CIRCUIT PNK PNK WIRE PNK WIRE PPL REAR DOME/ READING LAMPS (IF EQUIPPED) REMOTE CONTROL DOOR LOCK RECEIVER (BEHIND CENTER OF DASH) RIGHT FRONT DOOR COURTESY LAMP (IF EQUIPPED) RIGHT FRONT DOOR JAMB SWITCH RIGHT I/P COURTESY LAMP RIGHT ILLUMINATED VANITY MIRROR RIGHT REAR DOOR COURTESY LAMP (IF EQUIPPED) RIGHT REAR DOOR JAMB SWITCH (IF EQUIPPED) UNDERHOOD FUSE/RELAY CENTER UNDERHOOD LAMP W/ OVERHEAD CONSOLE W/ RKE W/O OVERHEAD CONSOLE W/O RKE W/O RKE W/ RKE WHT WIRE

ASH TRAY LAMP BLK WIRE BODY CONTROL MODULE (IN CENTER CONSOLE) BRN WIRE GARAGE DOOR OPENER LAMP HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES I/P FUSE BLOCK LEFT FRONT POWER WINDOW SWITCH LEFT REAR HEATED SEAT SWITCH LEFT REAR POWER WINDOW SWITCH OFF ORG/ WIRE PARADE MODE SW PARK PARK LPS FUSE 9 POWER OUTSIDE REARVIEW MIRROR SWITCH REAR STEREO CONTROLLER REAR WINDOW LOCKOUT SWITCH RHEO- STAT RIGHT FRONT POWER WINDOW SWITCH RIGHT REAR HEATED SEAT SWITCH RIGHT REAR POWER WINDOW SWITCH

AUDIO ALARM MODULE (ON CONVENIENCE CENTER) AUTOMATIC TRANSFER CASE CONTROL SWITCH (LUXURY) AUTOMATIC TRANSFER CASH SELECT SWITCH AUXILIARY HEATER CONTROL BASE BLK WIRE CARGO LAMP SWITCH (PICKUP ONLY) TRANSFER CASE SWITCH CONVEN- IENCE CENTER DAYTIME RUNNING LAMP (DRL)/ RADIO OVERRIDE SWITCH DAYTIME RUNNING LAMPS (DRL)/ RADIO OVERRIDE SWITCH DISPLAY DIM SIG DISPLAY DISPLAY DIM DIM SIG SIG FOG LAMP SWITCH FRONT AUXILIARY HVAC CONTROL LAMP GRN WIRE GRY WIRE HEADLAMP, PANEL DIMMER SWITCH HOT AT ALL TIMES HVAC CONTROL LAMP I/P FUSE BLOCK ILLUM FUSE 14 ILLUMINATION INFLATABLE RESTAINT I/P MODULE SWITCH INSTRUMENT CLUSTER LIFTGATE RELEASE SWITCH (SUBUR- BAN/ UTILITIY ONLY) LUXURY OFF ORG/ WIRE PARADE MODE SW PARK PARK LPS FUSE 9 PICKUP/ EXTENDED CAB ONLY PPL PPL PPL RADIO RADIO INFLATABLE RESTAINT I/P MODULE SWITCH REAR AUXILIARY HVAC CONTROL LAMP REAR AUXILIARY HVAC CONTROL SWITCH REAR WINDOW WIPER/ WASHER SWITCH RHEO- STAT SUBURBAN, UTILITY ONLY SWITCH (SUBUR- BAN/ UTILITIY ONLY) TRANSFER CASE SHIFT ILLUMINATION LAMP TRANSFER CASE SWITCH WHT WIRE

BLK WIRE COURTESY LAMPS CIRCUIT CTSY FUSE 3 FRONT DOME/ READING LAMPS HEADLAMP, PANEL DIMMER SWITCH COURTESY LAMPS HOT AT ALL TIMES I/P FUSE BLOCK INT LAMP OUTPUT ORG/ WIRE OVERHEAD CONSOLE READING LAMPS REAR DOME READING LAMPS REMOTE CONTROL DOOR LOCK RECEIVER (W/RKE) (BEHIND CENTER OF DASH) WHT WIRE

32 33 PPL 39 40 41 PPL AF FUEL PUMP RELAY (LEFT OF ENGINE COMPT) BLK WIRE BRN WIRE BRN/WHT WIRE DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FUEL GAUGE RELAY (LEFT OF ENGINE COMPT) FUEL GAUGE SELECT SWITCH GAS MASS SENSOR (RIGHT FRONT OF ENGINE) GRY WIRE GRY/BLK WIRE HIGH PRESSURE LOCK-OFF SOLENOID (END OF CNG FUEL TANK) IGNITION RELAY (LEFT OF ENGINE COMPT) LOCK-OFF RELAY (LEFT OF ENGINE COMPT) LOW PRESSURE LOCK-OFF SOLENOID (RIGHT MIDDLE OF ENGINE) LT BLU WIRE LT BLU/WHT WIRE LT GRN WIRE MIXTURE CONTROL VALVE MOTOR (RIGHT FRONT OF ENGINE) NCA WIRE ORG/ WIRE PNK 2 3 4 5 6 7 WIRE PNK 24 25 26 27 28 29 30 31 32 33 34 35 36 37 WIRE PNK PNK PNK 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 WIRE PNK PNK PNK WIRE PNK WIRE PPL PPL/WHT WIRE RED WIRE RED/BLK WIRE TAN WIRE TAN/WHT WIRE WHT WIRE YEL WIRE YEL/BLK WIRE

16 PPL 32 33 PPL AUTOMATIC TRANSMISSION INPUT SHAFT SPEED SENSOR (LEFT SIDE OF TRANSMISSION) BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRN WIRE BRN/WHT WIRE CONVENIENCE CENTER (UNDER LEFT SIDE OF DASH) DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE FUEL GAUGE FUEL PUMP, SENDER (IN FUEL TANK) FUEL TANK PRESSURE SENSOR (IN FUEL TANK) GAUGES FUSE 4 GRN WIRE GRY WIRE GRY/BLK WIRE HOT IN OFF, RUN OR START HOT IN RUN OR START I/P FUSE BLOCK INPUT INSTRUMENT CLUSTER INTAKE AIR TEMPERATURE SENSOR (IN AIR INTAKE DUCT) LT BLU/WHT WIRE LT GRN WIRE M/T ONLY MASS AIRFLOW SENSOR (IN AIR INTAKE DUCT) PNK (TAILLAMP EXTENSION HARN, 6 CM FROM THE FUEL PUMP HARN BREAKOUT) WIRE PNK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 WIRE PNK PNK PNK WIRE PNK WIRE PPL PPL/WHT WIRE RED WIRE RED/BLK WIRE SERVICE ENGINE SOON INDICATOR SIG IGN GRD PNK WIRE SPEEDOMETER TACHOMETER TAN WIRE TAN/BLK WIRE THROTTLE POSITION SENSOR (ON THROTTLE BODY ASSEMBLY) TRANS FUSE 20 UPSHIFT LAMP W/O DUAL FUEL TANK WHT WIRE YEL WIRE YEL/BLK WIRE

A/C REQUEST SIGNAL AIR CONDITIONING SYSTEM AIR INLET VLV MTR CTLR AUTOMATIC AUTOMATIC TRANSFER CASE SHIFT CONTROLLER BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BRAKE FUSE 18 BRN WIRE BRN/WHT WIRE CLUTCH PEDAL POSITION (CPP) SWITCH (AT TOP OF CLUTCH PEDAL BRACKET) CPP SW INPUT FOUR WHL DR SIG LO CRUISE CTRL SIG ENG 23 24 CRUISE CONTROL MODULE (LEFT REAR OF ENGINE COMPT, ON FIREWALL) DATA LINK CONNECTOR (UNDER LEFT SIDE OF DASH, LEFT SIDE OF STEERING COLUMN) DISTRIBUTOR DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ELECTRONIC BRAKE CONTROL MODULE (EBCM) (ON LEFT SIDE OF ENGINE COMPT) ELECTRONIC VARIABLE ORIFICE/ PASSLOCK CONTROL MODULE (CENTER OF DASH) FORCE MOTOR FEED TRANS INPUT SPEED RTN TRANS INPUT SPEED SIG EST OUTPUT SIG FORCE MOTOR RETURN GROUND GROUND SENSOR GROUND FUEL LEVEL INPUT SWITCH SIGNAL FUEL PUMP PRIME CONNECTOR (LEFT REAR OF ENG COMPT) FUEL PUMP RELAY GRN WIRE GROUND GRY WIRE GRY/BLK WIRE HIGH VOLTAGE COIL WIRE HOT AT ALL TIMES UNDERHOOD FUSE- RELAY CENTER ECMB FUSE HOT IN RUN I/P FUSE BLOCK IGN INPUT BRAKE SW INPUT INPUT IGNITION IGNITION COIL (TOP RIGHT REAR OF ENGINE) IGNITION CONTROL MODULE (RIGHT SIDE REAR OF ENGINE) IGNITION FEED IGN TIMING SIG. IGN COIL OUT IGNITION PRESSURE SWITCH INPUT PRESSURE SWITCH INPUT LT BLU/BLK WIRE LT BLU/WHT WIRE LT DK VSS INPUT SERIAL DATA SIG MANUAL OR SELECTABLE ORG/ WIRE PNK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 WIRE PNK IGNITION FOUR WHL DR SIG EGR VLV GROUND WIRE PNK PNK PNK WIRE PNK WIRE PPL PPL (OR PPL A/T M/T PPL PPL PPL PPL 420 OR PPL/WHT WIRE PRESSURE SWITCH INPUT RADIO RED WIRE RED/BLK WIRE SENSOR RETURN SHIFT IND LP OUT EGR VLV FEED SPEED SENSOR SPEED SENSOR INPUT STOPLAMP/ CLUTCH SWITCH INPUT VCM SIG STOPLAMP SWITCH (TOP OF BRAKE PEDAL) SWITCH SIGNAL TAN/BLK WIRE TRANSFER CASE CONTROL MODULE (UNDER DASH ON STEERING COLUMN SUPPORT BRACKET) TRANSFER CASE SWITCH (LEFT TOP OF TRANSFER CASE) TRANSMISSIONS SYSTEM UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENGINE COMPT) WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE