TM 10-3930-671-24 FIGURE NO.  17.1. ALTERNATOR OUTPUT AND SYSTEM TEST (45 Amp Systems) - This test will determine if the alternator is capable of producing  a  minimum  rated  output.    Position  load  control  knob  of  carbon  pile  to  the  "OFF"  position  prior  to  connecting leads  to  battery  terminals.    The  test  requires  that  a  test  ammeter  be  set  to  the  0-200  ampere  scale,  and  connected  in series with the alternator positive output terminal and battery positive terminal, as shown in Figure No.  17.1. Start the engine and allow it to run for a few minutes to stabilize component temperatures.  Adjust engine speed to 3000- 5000 alternator rpm.  Apply carbon pile load to the battery to induce highest alternator current output. Note voltage output.  Minimum acceptable (hot) alternator output should be 41-45 amperes.  Output voltage must remain between 13.0 and 15.0 volts. If  alternator  cannot  produce  the  required  output,  remove  from  engine  and  rebuilt.    Reduce  carbon  pile  load  on  battery immediately after testing to avoid discharging battery. System  voltage  drop,  between  the  alternator  and  the  battery,  is  tested  with  the  alternator  producing  10  amperes.    The maximum allowable voltage drop, between alternator and battery is .3 (three tenths) volt.  Excess voltage loss may require cleaning and tightening of all circuit connections or replacement of output cables between the alternator and the battery. ALTERNATOR DISASSEMBLY & COMPONENT TESTS BRUSH ASSEMBLY REMOVAL 1. Remove  regulator  to  gain  access  to  the  brush assembly cover (Figure No.  18). FIGURE NO.  18. 2 With brush assembly cover pulled down and away from back housing, remove two 8 X 1/2" tapping screws retaining brush assembly to housing (Figure No.  19). FIGURE NO.  19. F-285