4-69. BATTERY CHARGING AMMETER. (cont) Adjustment. Adjustment of the BATTERY CHARGING ammeter consists of zero setting the   meter   needle.   No other adjustment shall be attempted. (1) Open control panel access door. (2) Ensure that MASTER SWITCH is in OFF position. (3)  Needle  adjustment  screw  is located  on  face  of  meter  just  below center of dial face. (4)  Looking straight down   on meter  face, use screwdriver and care- fully  turn needle  adjustment screw until  needle  points  directly  at  “O” tick mark on meter scale. (5)  Close  control  panel  access door. b.  Removal. WARNING To  prevent  injury,  ensure  that battery  is disconnected  before performing maintenance o n electrical   components. a.  Test. (1) Disconnect battery cable plug connector  from  battery. (2)  Open  control panel access d o o r . (3) Loosen turnlock fasteners and open control panel. (4)   Tag   and   disconnect   wiring from back of BATTERY CHARGING ammeter (4, figure 4-43). ARMY TM  5-6115-612-12 MARINE  CORPS  TM  6115-12/7 AIR  FORCE T0 35C2-3-471-1 NAVY AG-320B0-0MM-000 (5) Remove nuts (1), lockwashers (2), and screws (3). (6)  Remove BATTERY CHARGING ammeter from control panel. c. Installation. (1)  Carefully place BATTERY CHARGING ammeter (4) in control panel. (2) Install screws (3), lockwashers (2), and nuts (1). Tighten securely. (3)  Remove tags and connect wiring  to  back  of  ammeter. Adjust meter  (paragraph  4-69a). (4) Close control panel and secure  with  turnlock  fasteners. (5) Close and latch control panel access door. (6)  Connect  battery  cable  plug connector to battery. 4-70. MASTER SWITCH. Maintenance  of the  MASTER  SWITCH  (8,  figure  4-43) consists  of  testing  and  replacement. To prevent battery is WARNING injury, ensure that disconnected  before performing maintenance on electrical  components. (1) Disconnect battery cable plug connector  from  battery. (2)  Open  control  panel  access door. 4-133