3-44 TM 9-2320-363-20-1 Table   3-1. Troubleshooting (Cont) Malfunction Test   or   Inspection Corrective   Action Step  5. Step    6. ELECTRICAL   SYSTEM   (CONT) Turn   Signal   and   Stoplight    Circuits   (Cont) Set   turn  signal  switch  in  left  turn  mode.   Install  jumper  leads  between connectors 30,    85,    and    86    to   their respective connectors at left flasher relay. Check for   +24 VDC at   left   flasher relay    connection 87. . If   +24    VDC is   present, go   to   step    6.    If   no   voltage is   present, replace left   flasher relay (pages 4-197, 4-198). Set    turn   signal    switch   in   left   turn    mode. Check    for   +24 VDC at   trailer receptacle connectors    421  B. . If   no   voltage is   present, repair    leads    421 B   (page    3-2). 5. ONE OF    THE LEFT TURN SIGNAL LIGHTS NOT OPERATING. Step   1. Inspect light   bulb. . Replace if   broken    or   defective Step    2. Remove lamp   from   defective left   turn    signal Check for   continuity    between contact points. . If   continuity    is   indicated, go   to indicated, replace lamp    (pages (pages 4-218, 4-284). light   (pages 4-218, 4-284). step   3.    If   no   continuity    is 4-218, 4-284). Step   3. Remove signal    light   lamp. Check for   continuity    between socket    and   ground. . If   continuity    is   indicated, repair    lead    60    (page    3-2). If   no continuity    is   indicated, repair    ground    lead (page    3-2). 6. LEFT TURN SIGNAL INDICATOR LIGHT NOT OPERATING, TURN SIGNALS OPERATING NORMALLY. Step 1. inspect light   bulb. . Replace if   broken    or   defective (page 4-174). Step 2. Disconnect lead   60A    from    warning light   bar.    Check for   +24    VDC at lead 60A. . If   +24    VDC is   present, troubleshoot warning light   circuit (page    3-60). If   no   voltage is   present, repair    lead   60A (page    3-2).