Figure 5-12. Alternator Test Setup

TM 10-3930-623-12

b. Inspect alternator for cracked housing, bent

shaft, or damaged drive pulley. Turn shaft by hand; it

should rotate freely with no catching or binding. Replace

or repair damaged alternator.

c. Alternator Test.

(1) Connect assembled alternator as shown

in figure 5-12. Make sure negative terminal is connected

to ground. Adjust load rheostat to obtain specified

output of 14 volts. Check amperage at 2000 alternator

rpm or 1000 engine rpm (cold); it should be 21 amperes.

Check amperage at 5000 alternator rpm or 2500 engine

rpm (cold); it should be 30 amperes. Operate alternator

until it is at operating temperature.

Check output

amperage; it should be 32 amperes.

(2) If output is not as specified, replace

d. Alternator Installation.

(1) Position alternator on mounting bracket;

secure with mounting bolt.

(2) Loosely attach alternator to adjusting strap

with cap screw. Move alternator down and slip belts

over pulley. Adjust belt tension as directed in paragraph

5-34d. and tighten cap screw on adjusting strap.

Connect alternator as

Figure 5-12. Alternator Test Setup

5-11