Shift interlock circuit, commercial chassis for GMC Forward Control P3500 (1985-1999)

85 30 PPL BLK WIRE BRAKE/ BRAKE/TRANSMISSION SHIFT INTERLOCK (BTSI) SOLENOID (ON STEERING COLUMN) BRN WIRE DIESEL DIESEL ONLY DK GRN/WHT WIRE ELECTRONIC BRAKE CONTROL MODULE (BELOW RADIATOR ON CROSSMEMBER) GASOLINE HOT IN RUN I-3 FUSE I/P FUSE BLOCK PARK/NEUTRAL POSITION AND BACKUP LAMPS SWITCH (LEFT OF TRANS) PPL TORQUE CONVERTER CLUTCH AND STOP LAMPS SWITCH (RIGHT SIDE OF STEERING COLUMN) TRANS- MISSION CONTROL MODULE (TCM) (LEFT INTERIOR FIREWALL) TURN SIGNAL FLASHER (ON FUSE BLOCK) TURN-B/U FUSE VEHICLE CONTROL MODULE (VCM) (LEFT SIDE OF ENG COMPT) IGN YEL WIRE