GMC Forward Control P3500 (1985-1999) brake pressure differential switch Wiring diagrams

ABS IND. BLK WIRE BLK/ WHT WIRE BRAKE IND BRAKE PRESSURE DIFFERENTIAL SWITCH BRAKE/ BRN WIRE DIESEL GASOLINE DK GRN WIRE ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR OF FIRST CROSSMEMBER) FUSIBLE LINK HOT AT ALL TIMES HOT IN RUN HOT IN RUN OR START GAUGES FUSE I-3 FUSE I/P FUSE BLOCK IGN ABS LAMP CONTROL BRAKE SW INPUT INSTRUMENT CLUSTER LEFT FRONT WHEEL SPEED SENSOR LFT FRT SENSOR (-) LT BLU WIRE LT GRN WIRE PNK WIRE PPL PPL PPL PUMP MOTOR POWER PUMP MOTOR GROUND RED WIRE RIGHT FRONT WHEEL SPEED SENSOR RT FRT SENSOR (-) LFT FRT SENSOR (+) RT FRT SENSOR (+) TAN WIRE TAN/WHT WIRE TCC/ STOPLAMP SWITCH UNDERHOOD FUSE-RELAY CENTER VEHICLE CONTROL MODULE (LEFT SIDE OF ENGINE COMPT) VEHICLE SPEED SIG VSS BUFFER (LEFT SIDE OF INTERIOR BULKHEAD) VSS SIG SERIAL DATA LINE SERIAL DATA SIGNAL BRAKE LAMP CONTROL EBCM GROUND WHT WIRE YEL WIRE YEL/BLK WIRE

5.7L A/C COMPRESSOR HIGH PRESSURE CUT OFF SWITCH A/C COMPRESSOR HIGH PRESSURE CUTOFF SWITCH BLK WIRE BRAKE PRESSURE DIFFERENTIAL SWITCH DATA LINK CONNECTOR DIESEL DK GRN WIRE ELEC ELECTRONIC BRAKE CONTROL MODULE FUEL HEATER FUEL PUMP FUEL PUMP RELAY FUEL PUMP RELAY (DIESEL) FUSE BLOCK BREAKOUT) GASOLINE GLOWPLUG CONTROLLER GLOWPLUG CONTROLLER (FEDERAL) GLOWPLUG CONTROLLER (CALIFORNIA) 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 IGNITION CONTROL MODULE INSTRUMENT CLUSTER M/T A/T MASS AIR FLOW SENSOR MECH NCA WIRE POWERTRAIN CONTROL MODULE POWERTRAIN/ VEHICLE CONTROL MODULE STARTER RELAY TRANSMISSION CONTROL MODULE (DIESEL) VCM/ PCM VEHICLE CONTROL MODULE VEHICLE SPEED SENSOR CALIBRATOR (DIESEL) VEHICLE SPEED SENSOR SHIELD A/T OUTPUT SPEED SENSOR SHIELD WATER IN FUEL INDICATOR SENSOR WHEEL SPEED SENSOR BREAKOUT) WHT WIRE

7.4L 7.4L 6.5L A/C COMPRESSOR CLUTCH A/C COMPRESSOR REFRIGERANT PRESSURE SWITCH AUDIO ALARM AUXILIARY ENGINE COOLANT FAN A/C PRESSURE SWITCH AUXILIARY ENGINE COOLANT FAN MOTOR BLK WIRE BRAKE PRESSURE DIFFERENTIAL SWITCH BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID BRAKE/ TRANS- MISSION SHIFT INTERLOCK SOLENOID RELAY CRUISE CONTROL MODULE DATA LINK CONNECTOR DAYTIME RUNNING LAMPS CONTROL MODULE PULSE WIPER CONTROL MODULE DAYTIME RUNNING LAMPS RELAY ELECTRONIC BRAKE CONTROL MODULE ENGINE COOLANT FAN MOTOR ENGINE COOLANT LEVEL SWITCH FUEL LEVEL SENSOR FUEL LIFT PUMP FUEL PUMP MODULE HEADLAMPS/ PANEL DIMMER SWITCH PARK BRAKE PULL BUTTON RELAY I/P DIMMER SWITCH I/P FUSE BLOCK INLINE TO STEERING COLUMN HARNESS INSTRUMENT CLUSTER LEFT SIDE MARKER LAMP NCA WIRE PARK BRAKE ACTUATOR POSITION SWITCH PARK BRAKE ALARM RELAY PARK BRAKE PRESSURE VALVE SOLENOID PARK BRAKE PUMP RELAY PARK BRAKE PUMP MOTOR PULSE WIPER CONTROL MODULE A/C COMPRESSOR CLUTCH RIGHT SIDE MARKER LAMP TO INSTRUMENT PANEL) VECHILE CONTROL MODULE (7.4L) POWERTRAIN CONTROL MODULE (6.5L) VEHICLE SPEED SENSOR CALIBRATOR WHT WIRE