CHARGING SYSTEM GROUND CIRCUIT
When you conduct this test, observe polarity
and connect the external volts lead to the
generator or alternator ground terminal. (See fig.
4-13.) Then adjust the load increase knob until
the ammeter scale indicates a current of 20
amperes for dc systems or 10 amperes for ac
systems. Also, observe the voltage reading on the
(3-volt) VOLTMETER scale and compare it with
the specifications for proper charging system
a s r e q u i r e d b y t h e v e h i c le
m a n u f a c t u r e r . I f t h e r e a d i n g i s w i t h in
specifications, you should proceed with a
regulator ground circuit resistance test.
Figure 4-13.-Ground circuit resistance test.
REGULATOR GROUND CIRCUIT
To conduct this test, set the volt lead selector to the
INT VOLTS position. Then, observing polarity,
connect the external volts lead to the generator or
alternator ground terminal and to the regulator ground
terminal. (See fig. 4-14.) Adjust the load increase knob
until the AMMETER scale indicates a current of 10
amperes. Also observe the reading on the (3-volt)
VOLTMETER scale and compare it with the
specifications. If the voltmeter reading exceeds 0.1 volt,
excessive resistance is in the ground circuit between the
regulator and the generator or alternator. Check the
regulator ground system for loose mounting bolts or a
damaged ground strap.
BATTERY DRAIN TEST
The purpose of this testis to determine if a discharge
current is flowing when all accessories and lights are
turned off. Any discharge at this time would indicate the
presence of partially shorted or grounded wires,
Figure 4-14.-Regulator ground circuit resistance test.