TM 5-6115-593-12 TO 35C2-3-463-1 Figure 4-54.  Coolant Temperature Transmitter Observe ohmmeter as temperature increases.  If the transmitter is functioning properly,  the  resistance  should  read  143 ±14 5 ohms at 120°G (49°C). (4)   The transmitter is not repairable.  If it does not  indicate  a  resistance  within  the  above range, it should be replaced. c. Replacement. (1)   Screw   temperature   transmitter   into   water manifold. (2)   Connect wire with washers and nut. (3)   Plug drain and close draincock. (4)   Fill radiator with coolant in accordance with table 4-1. 4-82.    TEMPERATURE  SWITCH.    (See  figure  4-40.) The temperature switch senses engine coolant temperature.  When coolant exceeds 217 ±  3°F  (103 ± 2°C),    the    normally    closed    contacts    open    and    the normally  open  contacts  close.    This  action  results  in automatic   shutdown   of   engine   operation   at   coolant temperatures exceeding 217 ± 3°F (103 ± 2°C). a. Inspection.      Inspect   switch   for   corrosion   and leakage, and ensure that the electrical connector     is     secure.          The     switch     is     not repairable and replacement is necessary when it fails to operate.  If the engine is not overheating and the units shuts down as though it were, or if the  engine  continues  to  operate  when  running hot, the switch should be removed and tested as a possible cause of trouble. b. Removal.  (See figure 4-55.) Loosen connector, pull    wiring    plug,    and    unscrew    temperature switch from water manifold. c. Test. (1)   Connect ohmmeter set to Rx1 scale across switch contacts. (2)   Suspend switch in a container of antifreeze. Switch  should  be  inserted  so  that  sensing element is completely immersed but connector end is out of antifreeze. (3)   Heat antifreeze gradually and stir so heat is evenly distributed. (4)   Check    temperature    of    antifreeze    with    a reliable thermometer. (5)   When   antifreeze   has   reached   214°F   (90° C),     the     switch     should     open     and     the ohmmeter should read less than 1 ohm. (6)   Allow antifreeze to cool.  As the temperature drops   to   below   212°F   (89°C)   the   switch should close and the ohmmeter should read infinite ohms. (7)   The  switch  is  not  repairable.  If  it  does  not operate within the above limits it should be replaced. b. VIBRATION     DAMPER     AND     CRACKSHAFT PULLEY.        (See    figure    4-40.)    The    vibration damper  and  crankshaft  pulley  are  mounted  on the   front   end   of   the   crankshaft.      Inspect   as follows: 4-120