TM 10-3930-671-24 c)    If   the   battery   is   discharged,   it   may   be defective     or     it     may     be     because     the charging system is not working properly.  If the     battery case is not cracked or damaged  and  otherwise  appears  to  be  in good  condition,  recharge  the  battery  and see   whether   it   holds   the   charge.      Also, check the charging system. Refer to Alternator Maintenance Procedures. d) Check    the    fan/alternator    drive    belt    for damage  and  correct  tension.    Replace  or adjust the belt, as necessary. NOTE • Just  as  a  discharged  battery  is  not necessarily bad, a charged battery is not   necessarily   good.      An   old,   or defective   battery   may   show   a   full charge   but   be   unable   to   produce adequate   electrical   energy   to   meet the heavy load demand of the starter motor.    The  only  way  to  tell  is  with  a load test. •   Battery   must   be   fully   charged   to perform load test. e) Perform  a  load  test  to  determine  whether the   battery   is   good   or   defective.      If   the starter still does not crank the engine, you will need to use a battery tester. Disconnect    the    battery    cables    at     the terminals.    Either  remove  the  battery  for testing, or connect the tester to the battery in  the  truck.    Refer  to  the  manufacturer’s instructions   for   recommended   load   test procedure using a battery tester.   Battery defective:        replace    battery.        Battery good:    continue   in   service   Replace   the battery,    if    necessary.        Reconnect    the battery    cables    in    the    correct    order    of installation (ground cable last). f ) If the battery and its connections check out satisfactorily    but    the    starter    still    won’t crank the engine,  the  problem  is  probably in  the  starter  motor,  the  solenoid  switch, the starter relay, the ignition switch, or the wiring. g) Check voltage at the starter solenoid "switch" (S) (I)   (R)   terminal,   while   attempting   to   crank   the engine.      Connect   the   voltmeter   between   the "switch"   terminal   and   the   frame   (body)   of   the starter   motor   or   the   battery   negative   terminal, and try to crank the engine. NOTE The    ignition    switch    has    a    circuit through   the   starter   relay   (magnetic switch)    and    neutral    start    switch, separate from the circuit through the starter relay to the starter solenoid. (1) If  voltage  is  0  or  less  than  7  volts,  check for    wiring    continuity    (broken,    loose,    or disconnected  wire)  or  defective  switches such  as  the  ignition  key  switch  or  starter relay  (magnetic  switch).    Also,  check  the starter motor-to-engine block ground connection and the battery negative (ground) cable connections. (2) If  the  voltage  is  over  7  volts,  the  starter solenoid is defective and must be repaired or replaced. F-302