TM 9-2320-364-20-2 2-1220 9.  BEACON LIGHT DOES NOT OPERATE (CONT). 3. Repair wire 1276 (see schematic Fig 2-28) or notify DS Maintenance. Verify repair, go to Step 9 of this Fault YES NO Horn operates, indicating circuit   breaker CB3 OK. Dome light operates, indicating   10 to 14 vdc to wire 1276. Wire 1435 OK. Wire 1276 faulty. Beacon light switch faulty. Wire 1413 faulty. Wire 1184 faulty. Relay R6 not grounded. Beacon relay R6 faulty. Wire 1029 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Voltage test. STE/ICE-R #89. If wire 1276 is loose, faulty, or shorted to ground, beacon light will not operate. WARNING 4. Replace beacon light switch (Para 7-27). Verify repair, go to Step 9 of this Fault. YES NO Horn operates, indicating circuit   breaker CB3 OK. Dome light operates, indicating   10 to 14 vdc to wire 1276. Wire 1435 OK. Wire 1276 OK. Beacon light switch faulty. Wire 1413 faulty. Wire 1184 faulty. Relay R6 not grounded. Beacon relay R6 faulty. Wire 1029 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Continuity test. STE/ICE-R #91. If continuity is not measured, beacon light switch is faulty. WARNING Is continuity measured between terminals 1 and 5 on beacon light switch? Are 10 to 14 vdc measured on wire 1276 at beacon switch connector, terminal 5? Read   WARNING on Page 2-1221 Read   WARNING on Page 2-1221