TM 9-2320-363-20-1 Table   3-1. Troubleshooting    (Cont) Malfunction Test   or   Inspection Corrective   Action ELECTRICAL   SYSTEM   (CONT) Instrument   Wiring   Circuits   (Cont) Step   2. Check  for  +12   VDC   at   ignition   run   power   bus   connector. . If   +12 VDC is   present, repair lead 81  C (page 3-2). If    no voltage is present, repair connector on ignition run power bus (page 3-2). 2. WATER TEMPERATURE GAGE DOES NOT    OPERATE. Step 1. Disconnect  lead  81C  from  water    temperature gage. Check for   +12 VDC at lead    81C. . If   +12    VDC is   present, go   to   step    2.    If   no   voltage is   present, repair    lead   81C (page    3-2). Step  2. Disconnect ground    lead    from   water    temperature gage. Check for   continuity between lead    and   ground. . If   continuity    is   present,    go   to   step   3.    If   no   continuity is indicated, repair   ground    lead   (page    3-2). Step    3. Disconnect lead    119    from   water    temperature gage. Check for   +8    to   +12 VDC at   water    temperature gage. l If   +8   to   +12    VDC is   present,    go   to step 4. If no voltage is present, replace water temperature gage (page 4-172). Step    4. Disconnect lead    119    from   water    temperature gage sensor. Check    for   +8   to +12 VDC at   lead 119. . If   +8    to   +12    VDC is   present, replace    water temperature gage sensor    (page    4-238). If   no   voltage    is   present, repair    lead    119 (page    3-2). 3. FUEL    PRESSURE GAGE DOES NOT OPERATE. Step 1. Disconnect lead    81 C   from   fuel    pressure    gage.    Check for   +12 VDC at lead    81C. . If   +12 VDC is   present, go   to   step   2.    If   no   voltage is   present, repair    lead   81 C   (page    3-2). Step    2. Disconnect ground    lead    from   fuel   pressure    gage. Check for   continuity between lead    and   ground. . If   continuity    is   present, go   to   step   3.    If   no   continuity is indicated, repair   ground    lead   (page 3-2). 3-63