TM 5-6115-593-12 TO 35C2-3-463-1 b. Engine Starting.  When the operator toggles spring-loaded  MASTER  SWITCH  S1  to  the START position, normal start/stop/run/ relay K5   becomes   energized   through   normally closed contacts 5 and 6, and normally open contacts 3 and 2 of S1.  Upon release of S1, relay K5 is held in its energized state by its selflatching   contacts   2   and   4.      With   K5 energized,   run   pilot   relay   K54   energizes through the normally open contacts 1 and 5 of    K5,    and    as    a    result    normally    open contacts 1 and 2 of K54 close.  Starter crank limit     relay     K3     now     energizes     through forward-biased CR1 and the following closed   contacts:   K19,   speed   switch   SS1, K6, K50, and K54.  At this time magnetizing current    is    applied    to    start    solenoid    L4 (through   K3   contacts   1   and   2),   and   the heavy  duty  contactors  of  L4  close,  bringing current   to   starter   motor   B2   causing   it   to crank   the   engine.   Simultaneous   with   the previously described action, fuel solenoid L1 and  engine  run  relay  K1  are  both  activated (through normally closed contacts K21, K19, K6, K50, diode CR23, and contacts 1 and 2 of K54), allowing the passage of fuel to the engine. Prior to starting, K1 normally closed contacts  place  a  short  across  terminals  22 and  23  of  governor  controller  A106.    This ultimately sets the engine's hydraulic governor  for  zero  fuel  output.    Energizing K1  at  start  time  negates  this  function  and allows the passage of fuel. c. Starter    Motor    Protection.    Depending    on which  occurs  first,  cranking  power  will  be applied until the engine reaches a speed in excess  of  600  rpm  or  total  cranking  time exceeds   30   seconds.      When   the   engine attains  a  speed  over  600  rpm  (in  less  than 30    seconds),    speed    switch    SS1    opens, subsequently   deenergizing   K3   and,   then, L4.   With   L4   deactivated,   cranking   action ceases when the contactors of L4 disconnect power from starter motor B2.  If the  engine  does  not  start,  that  is,  does  not reach  a  speed  in    excess  of  600  rmp,  and cranking   time   exceeds   approximately   30 seconds,  cranking  will  automatically  cease thereby  preventing  the  possible  burnout  of starter   motor   B2.   Initially,   when   cranking begins,  time  delay  relay  assembly  TD1  is turned  on  (through  closed  contacts  of  SS1, K6,  K50,  and  K54)  and  the  timing  process commences.      After   a   period   of   about   30 seconds,   TD1   stops   timing   and   connects overcrank  shutdown  relay  K19  to  +24V  DC through contacts of SS1, K6, K50, and K54 thereby energizing K19. K19 now energized, opens its normally closed contacts in series with    cranking    relay    K3    causing    K3    to deenergize,    and    subsequently,    power    is removed from B2.  To indicate that this has occurred,  OVER  CRANK  lamp  DS51  lights when it is returned to +24V DC through the normally   open   contacts   of   K19   (in   series with DS51) and the path consisting of SS1, K6,  K50,  and  K54.    If,  as  was  previously mentioned,   engine   speed   goes   over   600 rpm,   SS1   opens   and   the   just   described action does not occur. d. Ether  Starting.    As  an  aid  to  cold  weather starting, provisions are made to inject ether into  both  of  the  engine  air  intake  manifolds while   the   engine   is   being   cranked.   The application   of   this   highly   volatile   fluid   is controlled  by  the  ether  solenoid,  ether  aid control  relay  K24,  and  START  AID  switch S2.    During  crank  time,  K24  is  energized through   closed   contacts   of   K6,   K50,   and K54.        At    this    time    the    normally    open contacts of K24, which are in series with the ether aid control S2, close.  Operating S2 to the   ON   position   activates   the   ether   aid control solenoid causing a measured amount of ether to be loaded into the ether aid    device.    Upon    release    of    S2,    this measured    amount    of    ether    is    forcefully injected  into  the  air  intake  manifolds.    The ether aid device may be used at any engine speed up to 1200 rpm and for approximately 5 seconds afterwards (the 5-second delay is explained in subparagraph 1-14th(2), below). e. Louver     Operation     (Housed     Sets).     The auxiliary housing kit 1-23