TM 9-2320-364-20-2 2-1458 34.  ENGINE BRAKE DOES NOT OPERATE IN LOW (CONT). 4. Repair wire 1712 (see schematic Fig 2-38) or notify DS Maintenance.   Verify repair, go to Step 18 of this Fault. YES NO Reverse light operates   indicating 10 to 14 vdc to wire   1871. Dash lights operate indicating   10 to 14 vdc to circuit breaker   CB7. Engine brake harness OK. Circuit breaker CB7 OK. Wire 1712 faulty. Engine brake switch faulty. Wire 1713 faulty. Wire 1711 faulty. Wire 508 faulty. DDEC ECM faulty. TRANS relay R7 faulty. Wire 1839 faulty. Wire 211 faulty. Relay R8 wire 1871 faulty. Wire 213 faulty. ATEC ECU faulty. Retarder relay R8 faulty. Wire 1716 faulty. Circuit breaker CB11 wire 1871   faulty. Wire 1711 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Voltage test. STE/ICE-R #89. If wire 1712 is loose, faulty, or shorted to ground, engine brake will not operate. WARNING 5. Replace engine brake switch (Para 7-27).   Verify repair, go to Step 18 of this Fault. YES NO Reverse light operates   indicating 10 to 14 vdc to wire   1871. Dash lights operate indicating   10 to 14 vdc to circuit breaker   CB7. Engine brake harness OK. Circuit breaker CB7 OK. Wire 1712 OK. Engine brake switch faulty. Wire 1713 faulty. Wire 1711 faulty. Wire 508 faulty. DDEC ECM faulty. TRANS relay R7 faulty. Wire 1839 faulty. Wire 211 faulty. Relay R8 wire 1871 faulty. Wire 213 faulty. ATEC ECU faulty. Retarder relay R8 faulty. Wire 1716 faulty. Circuit breaker CB11 wire 1871   faulty. Wire 1711 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Continuity test. STE/ICE-R #91. If engine brake switch is faulty, engine brake will not operate. WARNING Are 10 to 14 vdc measured on wire 1712 at engine brake switch connector, terminal 2? Is continuity measured at engine brake switch, terminals 2 and 8? Read   WARNING on Page 2-1459 Read   WARNING on Page 2-1459