TM 9-2320-280-20-1 KNOWN INFO POSSIBLE PROBLEMS KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION YES NO YES 2-342           Change 1 DISCONNECT WIRE 67A AND 67B FROM BRAKE WARNING PRESSURE SWITCH, WIRE 67C FROM PARKING BRAKE SWITCH. DISCONNECT THE PCB/DISTRIBUTION BOX BODY HARNESS CONNECTOR. CONNECT A JUMPER WIRE BETWEEN WIRES 67A AND 67B. DOES THE LIGHT GO “OUT”? CONNECT PCB/DISTRIBUTION BOX BODY HARNESS. DOES THE LIGHT STAY “OFF”? BRAKE WARNING   LIGHT WON'T GO OFF WIRING PARKING BRAKE SWITCH PCB/DISTRIBUTION BOX BRAKE WARNING   PRESSURE SWITCH WIRING OK REPAIR OR REPLACE WIRING HARNESS REPLACE PCB/DISTRIBUTION BOX START 2 3 1. STE/ICE-R TEST 89 (Page 2-750) 2. MULTIMETER 1. STE/ICE-R TEST 91 (Page 2-752) 2. MULTIMETER (RESISTANCE) If the lamp stays on with the PCB/distribution box, valve switch and park brake switch disconnected, the problem is in the wiring. When the protective control box/distribution box is connected, the light should not come on. If it does, the PCB/distribution box is faulty. BRAKE WARNING   PRESSURE SWITCH PCB/DISTRIBUTION BOX PARKING BRAKE SWITCH DIAGNOSTIC FLOWCHART INSTRUMENTS CIRCUIT REASON FOR QUESTION TEST OPTIONS NO KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION YES BLEED BRAKE SYSTEM. DOES THE LIGHT STAY  “ON”? BRAKE WARNING   LIGHT WON'T GO OFF WIRING PARKING BRAKE SWITCH PCB/DISTRIBUTION BOX BRAKE WARNING   PRESSURE SWITCH END OF TEST 1 NONE If the lamp stays on, it could be that the hydraulic brake system has a fault and might require bleeding. NO GO TO 4, Page 2-344