Case 580SR Service Manual page 977

www.maskinisten.net
PRELIMINARY TESTS
The preliminary tests may be carried out without re-
moving the charging circuit components, these tests
help check the following items:
Z Connections of the alternator cables
Z Charging current and regulated voltage of the alter-
nator
Z Voltage lowers in the alternator charging circuit
Z Maximum flow of the alternator
Required devices:
Z Voltmeter (0-30 V, moving coil)
Z Millivoltmeter (0-1 V)
Z Ammeter (0-110 A, moving coil)
Z Variable resistance of 1.5 Ohm, 110 A
NOTE: most testing instruments sold in shops group
together several measurement functions in a single
device. Use these devices in accordance with the
manufacturer's instructions.
CHECKING THE CONNECTIONS OF THE
ALTERNATOR CABLES
Z Disconnect the battery.
Z Disconnect the terminals B+ (2) and L (3) from the
alternator.
Z Reconnect the battery and turn the ignition key
without starting the motor. Connect a voltmeter (4)
between each terminal (B+ or L) and the ground
(1). The voltmeter must show the battery voltage.
Z If there is no battery voltage, the external cable has
a continuity fault; in this case, check the entire cir-
cuit and carry out the necessary repairs.
Z Connect the terminal L indicator lamp wire to the
ground. The indicator lamp should turn on.
Z Disconnect the battery and reconnect the cables to
the alternator.
NOTE: if the indicator lamp does not turn on after
having reconnected the alternator, the regulator of
the alternator or the rotor circuits is defective. Make
sure that terminal L is clean, then check the compo-
nents of the alternator as indicated in this chapter.
SECTION 55 - ELECTRICAL SYSTEM
Copyright ©
149