TM  10-3930-638-24&P 2-20.   BATTERY   SYSTEM   TROUBLESHOOTING   (cont) MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION 1. ALL ELECTRICAL SYSTEMS ARE WEAK (cont) Step 3. Connect voltmeter leads to positive and negative  posts  of  one  battery. Note  voltmeter  indication  while  an  assistant cranks engine. Repeat  for  remaining  battery. If  voltmeter  indicates  less  than  9.6  Vdc, check the specific gravity of each battery cell. If there is more than 25 points variation (0.025)  between  individual  cells,  replace battery (para 2-33b). 2. BATTERIES ARE HOT OR USE EXCESSIVE WATER Connect voltmeter leads to alternator BAT terminal and case (ground). With  all  accessories  turned  off,  operate  engine  at  1800 rpm  and  note  voltmeter  indication. If voltmeter indicates more than 31 Vdc, replace alternator (para 2-26). 2-21.   STARTING   SYSTEM   TROUBLESHOOTING MALFUNCTION TEST OR INSPECTION CORRECTIVE  ACTION 1. STARTER CRANKS TOO SLOWLY Step  1.  Connect  positive  voltmeter  lead  to  solenoid  B terminal and negative voltmeter lead to solenoid M terminal. Note  voltmeter  indication  while  assistant cranks engine. a. If voltmeter indicates less than 0.3 Vdc, proceed to step 2. b. If voltmeter indicates more than 0.3 Vdc, replace starter assembly (para 2-27a). 2-100