TM 9-2320-364-20-2 2-1238 10.  HEADLIGHT(S) DO NOT OPERATE (LOW BEAM) (CONT). 8. Is continuity measured on wire 1435 between relay R1, terminal 86 and a known good ground? Repair wire 1435 (see schematic Fig 2-31) or notify DS Maintenance. Verify repair, go to Step 14 of this Fault. YES NO Circuit breakers CB1 and CB4   not tripped. Work lights operate indicating   10 to 14 vdc to circuit breaker   CB1. Headlight lamp OK. Headlight wire 1006 OK. Headlight wire 1435 OK. Circuit breaker CB1 OK. Wire 1927 OK. Wire 1049 OK. Headlights relay R1 wire 1435   faulty. Headlights relay R1 faulty. Wire 1017 faulty. Dimmer relay R5 faulty. Wire 1006 faulty. Wire 1292 faulty. Headlight switch faulty. Wire 1049 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Continuity test. STE/ICE-R #91. If relay R1 is not grounded through wire 1435, headlights will not operate. WARNING 9. Are 10 to 14 vdc measured on wire 1017 at headlights relay R1, terminal 87? Replace headlights relay (Para 7-95). YES NO Circuit breakers CB1 and CB4   not tripped. Work lights operate indicating   10 to 14 vdc to circuit breaker   CB1. Headlight lamp OK. Headlight wire 1006 OK. Headlight wire 1435 OK. Circuit breaker CB1 OK. Wire 1927 OK. Wire 1049 OK. Headlights relay R1 wire 1435   OK. Headlights relay R1 faulty. Wire 1017 faulty. Dimmer relay R5 faulty. Wire 1006 faulty. Wire 1292 faulty. Headlight switch faulty. Wire 1049 faulty. KNOWN INFO POSSIBLE PROBLEMS TEST OPTIONS REASON FOR QUESTION Voltage test. STE/ICE-R #89. If 10 to 14 vdc are not measured, headlights relay R1 is faulty. WARNING Read   WARNING on Page 2-1239 Read   WARNING on Page 2-1239