GMC Suburban C2500 (1985-1999) spark retard signal a/c on signal in Wiring diagram

4 5 PPL 413 412 PPL AIR CONDITIONING SYSTEM (A/C COMPRESSOR CLUTCH) AIR SWITCH SOLENOID (5.0L, 5.7L- PICKUP ONLY) (RIGHT FRONT OF ENGINE) AIR SWITCH SOLENOID IAC COIL B LO IAC COIL B HI IAC COIL A HI IAC COIL A LO ANTI-LOCK BRAKE SYSTEM BLK WIRE BLK/RED WIRE BLK/WHT WIRE BRN WIRE BRN/WHT WIRE CRANK SIGNAL COOLANT TEMP SENS SIG MAP SENSOR SIGNAL DATA LINK CONNECTOR (UNDER LEFT SIDE OF I/P) DISTRIBUTOR REF HI DK BLU WIRE DK GRN WIRE DK GRN/WHT WIRE ECM IGN FUSE EGR SOLENOID MIL INDICATOR CTRL ENGINE CONTROL MODULE (UNDER RIGHT SIDE OF I/P) FUEL PUMP RELAY CTRL FUEL PUMP SIGNAL INPUT DISTRIBUTOR REF LO FUSE LINK (20 GA- GAUGES FUSE GRY WIRE HOT AT ALL TIMES HOT IN RUN, BULB TEST OR START HOT IN START FUSE BLOCK CRANK FUSE IDLE AIR CONTROL UNIT (RIGHT REAR OF TBI UNIT) IGNITION CONTROL (IC) IC BYPASS OXYGEN SENSOR GROUND OXYGEN SENSOR SIGNAL INJ FUSE INJECTOR 1 DRIVER INJECTOR 2 DRIVER INSTRUMENT CLUSTER LT BLU/BLK WIRE LT BLU/WHT WIRE LT GRN WIRE LT GRN/BLK WIRE LT GRN/WHT WIRE ORG/ WIRE OXYGEN SENSOR (LEFT SIDE EXHAUST MANIFOLD) PNK/BLK WIRE PPL PPL/WHT WIRE RED WIRE SERVICE ENGINE SOON INDICATOR SPARK RETARD SIGNAL A/C ON SIGNAL IN SYSTEM GROUND SYSTEM GROUND SENSOR RETURN GROUND TAN WIRE TAN/BLK WIRE TAN/WHT WIRE THROTTLE BODY FUEL INJECTOR #1 (TOP OF THROTTLE BODY UNIT) THROTTLE BODY FUEL INJECTOR #2 (TOP OF THROTTLE BODY UNIT) TP SENSOR SIGNAL UP- SHIFT LAMP UPSHIFT LAMP CTRL DLC SERIAL DATA DLC DIAGNOSTIC TEST VSS BUFFER SIGNAL WHT WIRE WHT/BLK WIRE YEL WIRE YEL/BLK WIRE