TM 5-3805-261-34
CHARGING SYSTEM MAINTENANCE.
4-5.
Alternator (Bosch). (Sheet 7 of 12)
TESTING
2.
Discharge capacitor (12) ground .
3.
Set up alternator on test bench connecting
voltmeter, ammeter, battery and carbon pile
(Figure 4-30).
4.
Test regulator (17, Figure 4-29)
on
alternator.
CAUTION
Observe correct polarity when connecting voltmeter.
Damage to vehicle may result if you fail to follow this
procedure.
5.
Set load current to 7 amps by adjusting carbon
pile at a test speed of 5000 rpm. If after one
minute, voltage does not read between 26.5
volts and 28.5 volts, replace regulator (17).
6.
Test field coil (24) for opens or shorts. Removal
of only regulator (17) is necessary. Connect
ohmmeter to two wire assemblies of field coil
(24). Replace field coil (24) if test s not 7 to 9
ohms.
7.
Test field coil (24) for shorts to frame. Connect
ohmmeter to the (B-) terminal and then to each
of the two field coil (24) wire assemblies. If
readings are not high, field coil (24) is shorting to
frame and replacement is necessary.
Figure 4-30.
Go to Sheet 8
4-29
