TM 10-3930-669-20 WARNING Remove  all  jewelry  such  as  rings,  dog  tags,  bracelets,  etc.    If  jewelry  contacts  battery terminal,  a  direct  short  may  result  in  instant  heating  of  tools,  damage  to  equipment,  and injury or death to personnel. GAUGE OPERATION TEST (1) Remove  and  ground  sensor  wire  16 (Para 7-42) (2) Set   MAIN   POWER   switch   to   ON position (TM 10-3930-669-10). (3) Set engine switch to ignition position (TM 10-3930-669-10). (4) Observe  gauge  needle  for  reading. If  gauge  has  a  full  scale  deflection, perform  Steps  (5)  through  (7)  below and     replace     oil     pressure     sensor (Para 7-42). (5) Install sensor wire 16 (Para 7-42). (6) Set engine switch to off position. (7) Set   MAIN   POWER   switch   to   OFF position. 2-61